Improved Methods Of Plant Breeding Using High-Throughput Seed Sorting
20170295735 · 2017-10-19
Inventors
Cpc classification
A01H1/08
HUMAN NECESSITIES
International classification
Abstract
The present disclosure describes improved methods of plant breeding using rapid seed sorting processes. More particularly, it relates to the application of automated systems and methods that rapidly and nondestructively measure, classify, and sort seeds to improve the rate, efficiency, and accuracy of selection decisions and other processes related to improving crop genetics.
Claims
1. An improved method of breeding haploid plants comprising: a. creating a first set of at least two distinct haploid plant populations in the form of seeds, such that at least one population of the set comprises a frequency of haploid embryos, b. sorting at least two plant populations in the first set using a high-speed sorter to create a second set of distinct populations, each distinct population in the second set comprising a frequency of haploid embryos that is greater than the frequency of haploid embryos in the corresponding set 1 population from which the second population was derived, c. determining the likelihood that a plant appearing in set 1 contains at least one trait, and d. selecting at least one plant from at least one population in set 1 to advance in a breeding pipeline based on the outcome of step c.
2. The method of claim 1, wherein step b. is performed during or prior to performing step d.
3. The method of claim 1, wherein step b. is performed prior to step d.
4. The method of claim 1, wherein at least one of the haploid plant populations in set 1 is derived by crossing a parent plant with a maternal haploid inducer.
5. The method of claim 4, wherein the advancing of at least one population in the breeding pipeline comprises creating a doubled-haploid plant from a haploid embryo that appeared in set 1.
6. The method of claim 5, wherein less than 20% of the populations of set 2 are selected for advancement in the breeding pipeline in step d.
7. The method of claim 5, wherein less than 30% of the populations of set 2 are selected for advancement in the breeding pipeline in step d.
8. The method of claim 5, wherein less than 40% of the populations of set 2 are selected for advancement in the breeding pipeline in step d.
9. The method of claim 5, wherein less than 50% of the populations of set 2 are selected for advancement in the breeding pipeline in step d.
10. The method of claim 5, wherein less than 60% of the populations of set 2 are selected for advancement in the breeding pipeline in step d.
11. The method of claim 5, wherein less than 70% of the populations of set 2 are selected for advancement in the breeding pipeline in step d.
12. The method of claim 5, wherein less than 80% of the populations of set 2 are selected for advancement in the breeding pipeline in step d.
13. The method of claim 5, wherein less than 90% of the populations of set 2 are selected for advancement in the breeding pipeline in step d.
14. The method of claim 5, wherein less than 95% of the populations of set 2 are selected for advancement in the breeding pipeline in step d.
15. The method of claim 1, wherein the step of determining which plants contain a desired trait is performed on plants after the plants have germinated.
16. The method of claim 1, wherein the step of determining which plants contain a desired trait comprises assessing the yield potential, disease resistance, or other performance data of a parent, ancestor, progeny, or other related germplasm growing in a field, greenhouse, or other area suitable for growing plants.
17. The method of claim 1, wherein performing step c. comprises genotyping to determine whether a plant contains a certain trait.
18. The method of claim 1, wherein the genotyping comprises using a molecular marker.
19. The method of claim 1, wherein the genotyping comprises detecting or quantifying the presence of a nucleic acid sequence produced by a plant in set 1.
20. The method of claim 1 wherein the rapid haploid sorter system comprises sorting seeds using data derived from performing an NMR analysis on at least one of the seeds from set 2.
21. The method of claim 20 wherein the rapid haploid sorter system detects an NMR signal associated with the expression of seed oil content.
22. The method of claim 1 wherein at least 10,000 seeds are haploid sorted in the breeding pipeline during any 12-month period.
23. A method of creating populations of doubled haploid plants in a doubled haploid production pipeline wherein a rapid haploid seed sorter is used to sort populations of haploid seeds derived from inducer crosses and wherein the number of haploid populations sorted is greater than the number of haploid populations that are advanced onto later steps of the breeding pipeline.
24. The method of claim 23, wherein advancing a population in the breeding pipeline comprises doubling the chromosome number of at least one cell of at least one embryo in the population.
25. The method of claim 24, wherein the number of induced haploid populations that are sorted in the breeding pipeline exceeds the number of induced haploid populations that are advanced in the pipeline by a factor of 10% during any 12-month period of time.
26. The method of claim 24, wherein the number of induced haploid populations that are sorted in the breeding pipeline exceeds the number of induced haploid populations that are advanced in the pipeline by a factor of 30% during any 12-month period of time.
27. The method of claim 24, wherein the number of induced haploid populations that are sorted in the breeding pipeline exceeds the number of induced haploid populations that are advanced in the pipeline by a factor of 50% during any 12-month period of time.
28. The method of claim 24, wherein the number of induced haploid populations that are sorted in the breeding pipeline exceeds the number of induced haploid populations that are advanced in the pipeline by a factor of 80% during any 12-month period of time.
29. The method of claim 24, wherein the number of induced haploid populations that are sorted in the breeding pipeline exceeds the number of induced haploid populations that are advanced in the pipeline by a factor of 100% during any 12-month period of time.
30. The method of claim 24, wherein the number of induced haploid populations that are sorted in the breeding pipeline exceeds the number of induced haploid populations that are advanced in the pipeline by a factor of 500% during any 12-month period of time.
31. A high-throughput method for bulking a population of doubled haploid seeds, the method comprising: providing a first population of seeds comprising haploid seeds; sorting the first population of seeds using a rapid haploid sorter system to accumulate a second population of seeds comprising haploid seeds, wherein the second population of seeds is substantially devoid of diploid seeds; selecting one or more individual seeds exhibiting at least one preferred characteristic from the second population of seeds; producing doubled haploid seeds from the selected seeds; and cultivating plants or plant tissue from the selected doubled haploid seeds.
Description
DETAILED DESCRIPTION
[0020] The following description is merely exemplary in nature and is in no way intended to limit the present teachings, application, or uses. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope described herein. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
[0021] Embodiments described herein include methods of using rapid seed-sorting devices to accumulate pools (or populations) of haploid seeds substantially devoid of diploid seeds. Particular embodiments of rapid seed sorting devices suitable for use with the methods of the present invention are described in co-owned U.S. patent application Ser. No. 14/206,238 (filed Mar. 12, 2014), which is incorporated herein by reference in its entirety. For example, in some embodiments of the present methods, a rapid seed-sorting device using an NMR signal is employed to rapidly distinguish and sort haploid vs. diploid seeds, for example, as described in U.S. patent application Ser. No. 14/206,238. In other embodiments, other suitable devices for the rapid sorting of seed can be used.
[0022] Following rapid haploid sorting, selected seeds can be doubled using any chromosome doubling method known in the art, including high-throughput and/or automated doubling systems and methods.
[0023] A rapid haploid seed sorter could be used at any point in a breeding program where a user desires to separate seeds based on their ploidy level. Applicants do not intend to limit the use of rapid haploid seed sorting systems for sorting populations of seeds only derived from induction crosses.
[0024] In one embodiment, the systems and methods described herein allow for new methods of “mass sorting” haploid seed, described herein as using a rapid haploid sorter to sort populations of seeds before or during the time that selection decisions among the populations are made, i.e. before or while the process of determining which populations contain at least one seed with at least one characteristic at a frequency the user desires to maintain, increase, or decrease in a breeding program are performed. In one embodiment, a breeding program employs a rapid seed sorter to sort induced haploid populations as part of a “DH pipeline”, a multi-step process that doubles the chromosome numbers of at least one cell of a haploid plant. These analyses could include any evaluation, test or ranking system that influences selection decisions, including characterizing the induction rate (i.e. induction “performance”) of an induced hybrid, or data characterizing the breeding value of one or more parents of an induced hybrid (e.g. an inbred's general combining ability), or chipping and genotyping at least one seed of at least one induced haploid population. In contrast to current methods known in the art, a user employing mass sorting will typically expend a large portion of their total haploid sorting resources on populations that the user realizes will later fail one or more selection thresholds set by the user, and thus will not be selected for advancement to the next breeding cycle. Mostly due to costs, this approach is counter-intuitive using current methods in the art, but rapid haploid seed sorting systems and devices will make mass sorting a practical and worthwhile strategy in a large breeding program.
[0025] In certain embodiments, the term “large”, when used to describe a breeding program, breeding pipeline, and/or a DH pipeline, can include any series of steps made by an institution, corporation, machine, system, or group of at least one person wherein more than 10,000 seeds are subjected to haploid sorting techniques or technologies during any 12-month period. In certain embodiments, a large breeding pipeline is one that haploid sorts more than 10,000, 20,000, 30,000, 40,000, 50,000, 60,000, 70,000, 80,000, 90,000, 100,000, 110,000, 120,000, 130,000, 140,000, 150,000, 160,000, 170,000, 180,000, 190,000, 200,000, 210,000, 220,000, 230,000, 240,000, 250,000, or more than 250,000 seeds in any single 12-month period.
[0026] In certain embodiments, the systems and methods described herein allow for the “late sorting” of seed, wherein rapid haploid sorting is implemented after or during the time when selections among potential haploid populations are made and allows for time to collect and analyze additional phenotypic, genotypic and/or other information. Incorporating a rapid haploid sorter after selection permits a user to make a large number of accurate selections based on analyses completed after harvest and before planting deadlines. This is because a user can sort so rapidly, e.g. 5 or more seeds per second, that only minutes or hours are typically needed to sort an entire induced haploid population comprising thousands, tens of thousands, or more. This moves the deadline to start sorting considerably closer to the planting deadline, making available significant savings in time that can be re-allocated to other processes, such as improving selection accuracy. Late sorting has the added advantage of saving sorting resources until after it is known which populations will satisfy the selection criteria set by the user.
[0027] In still a further embodiment, the systems and methods described herein enable “over induction”, defined as a breeding strategy wherein significantly more induction progeny seed is generated in a DH pipeline than are subjected to the subsequent doubling steps of the pipeline. Thus, over induction effectively relaxes the selection intensity set by limitations of doubling and other downstream DH-related processes. This is because incorporating a rapid haploid seed sorter into a breeding pipeline frees up considerable time that can be reallocated to performing highly accurate selections between the time the induction populations are planted, harvested, and processed and planting deadlines. As a consequence, more false positives will be eliminated (as defined here, a false positive is a population that is selected, but in reality fails to meet a selection threshold set by the user), which in turn frees up more resources that can be applied to performing more induction crosses and testing a greater number of haploid progeny. This additional objective testing, in turn, results in fewer false negatives that would have been eliminated if manual sorting methods were used (as defined here, a false negative is a population or seed that is not selected, but in reality satisfies the selection threshold set by the user). Thus, over induction is based on the realization that a rapid haploid seed sorter can actually make it more efficient to sort large numbers of seeds that are unlikely to be selected for advancement at later points in the breeding pipeline (e.g. for example, planting and/or reproduced to increase in number, selfing or crossing with other plants, chromosome doubling, and/or transformation). This idea is new because rapid haploid sorting now makes it possible to perform more accurate selections utilizing new information resulting from performance tests of the parents, ancestors, or progeny of the populations in the breeding pipeline (e.g. field yield testing) and still meet target planting deadlines and/or meet deadlines to perform other steps later in the pipeline (e.g. doubling).
[0028] Selection methods and devices for determining whether seeds contain a desired trait could be used in conjunction with rapid haploid seed sorting, such as those that collect image data, (e.g. U.S. Pat. No. 8,253,054, U.S. Pat. No. 7,600,642, and/or a color seed sorter (e.g. Color Seed Sorter by National Manufacturing), and/or systems and devices that that chip and/or genotype seed (e.g. U.S. Pat. Nos. 7,611,842, 7,830,516, and 7,685,768), and/or an automated seed counter (e.g. the elmor 650 Multi-Channel Counter), or any other device that can be used to detect or identify seeds or evaluate plant phenotypes, genotypes, or performance.
[0029] In other embodiments, a rapid haploid seed sorter could be used to assess the performance of an inducer. For example, a rapid haploid seed sorter that assesses the oil content of seeds derived from crosses with a high-oil inducer, e.g. as described in U.S. patent application Ser. No. 14/206,238, could be used to determine whether hybrid seeds derived from a particular inducer cross lack a specified threshold of oil content. In this way, inducers that generate offspring that are difficult to haploid sort could be efficiently eliminated and substituted by better performing inducers.
[0030] A rapid haploid seed sorter can also be used to assess inducer performance based on induction rate. For example, a rapid seed sorter could be used to rapidly determine the induction rates derived from inducing a set of hybrids with a particular inducer. This would rapidly provide accurate induction rate performance data for a given inducer and permit a user to rank an inducer's performance relative to the induction rates of other inducers tested in a similar way. These types of tests can also be used to evaluate the ability of a given population to be induced. Test results ranking a given population's tendency to perform better with a given inducer, or among a set of inducers, relative to other materials can be used to drive future selection decisions about the parents of that population and other materials tested in a similar way.
[0031] Embodiments of this invention also include using a rapid haploid seed sorter to sort seeds based on any characteristic the sorter can measure, regardless of whether the characteristic is linked to ploidy level. For instance, a population of hybrid seeds derived from crossing two elite inbreds could be screened to identify and select those seeds which exhibit a threshold level of any trait the rapid haploid seed sorter can measure. In one example, the rapid haploid seed sorter described in U.S. patent application Ser. No. 14/206,238 detects an NMR signal and weight for each seed that passes through it. Consequently, such a system could be used to screen any population of seeds to identify and select those exhibiting a threshold value of any characteristic an NMR signal can measure and differentiate, such as weight, water content, or oil content. Other systems that haploid sort using technologies alternative to NMR could be similarly adapted to assay and sort seeds based on any criterion the sorter uses to identify and distinguish.
[0032] It also is envisioned that concepts described herein could be used in conjunction with rapid seed sorters that detect ploidy level by quantifying the frequency of nucleotide sequences among a population of seeds, e.g. as described in U.S. patent application Ser. No. 13/819,490, which is incorporated herein by reference in its entirety. Thus, embodiments of this invention are not limited to the specifics of any particular type of rapid haploid seed sorter, and could be applied to sorters that use visible light, NMR, X-ray, MRI, or any other kind of signal statistically correlated to the presence of a trait the user desires to measure. In one embodiment, the high-speed sorter detects the presence of at least one reporter molecule that binds to at least one specified nucleic acid or amino acid sequence that the user wishes to use to differentiate the seeds in a population. In other embodiments, the high-speed sorter is used to differentiate seeds based on the presence or absence of particular isotopes, e.g. C12 vs. C14. In some embodiments, this detection is accomplished by the use of rapid mass spectrometry.
[0033] Furthermore, rapid seed sorters could be used to sort and/or phenotype seeds for multiple traits at substantially the same time for any combination of traits the sorter is able to identify and discriminate. For example, it is envisioned that a rapid seed sorter using NMR technology to detect oil levels could sort seeds based on ploidy, and also sort seeds based on their water content as they pass through the device. In this embodiment, a user could set an NMR sorter to rapidly sort a population of seed derived from an induction cross so as to provide the user with a population of pure haploid seed wherein each seed contains no more than a threshold level of water that was set by the user. The data generated by this process could also be used to make other relevant breeding decisions, like parent selection. Rapid haploid seed sorters using technologies other than, or in addition to, NMR could be used to sort seeds based on any criteria the rapid haploid sorter has the capacity to detect and measure.
[0034] Additionally, in certain embodiments, a rapid seed sorter could be used in conjunction with any other methods, processes, or technologies useful for sorting or analyzing plants in order to further improve the efficiency of a breeding pipeline. These could be employed in parallel, serial, cyclical, and or substantially any other arrangement that a user desires using various machines in different combinations. For example, a user could employ a rapid optical seed sorter to sort seeds based on a desired characteristic prior to or after the seeds are sorted by a rapid seed sorter using NMR technology. It is also envisioned that multiple different combinations of seed sorting technologies could be employed in the same device, such that seeds are sorted by multiple sections of the same machine wherein each section sorts seeds based on a different set of criteria or technology (e.g. a machine that sorts seeds based on oil properties that are detected by an NMR system of the machine, and sorts seeds based on the size and/or shape of an embryo as characterized by an X-ray imaging system of the same machine).
[0035] Embodiments of this invention include mass sorting during or immediately following harvest. In some examples, seeds from induction crosses are sorted within a few hours, or days, of being harvested. In other examples, haploid seed sorting occurs during harvest by a rapid seed sorter deployed in the harvest location. A field-deployed rapid seed sorter sorting seeds based on optical criteria could be mounted directly to a harvester such that seed populations are sorted before leaving the harvester, or before being removed from the cob (shelled). A field-deployed rapid seed sorter unit could also be separable from the harvester and arranged to receive harvested seed from the harvester, e.g. a pull-behind unit or a self-propelled unit. A sorter could also be deployed nearby a field being harvested, such that the seed is shuttled from the harvester in the field to the sorter outside of the field. A rapid seed sorter could also be arranged to receive seed shuttled from multiple fields being harvested substantially simultaneously.
[0036] Thus, users will be able to make ready for germination, or planting, populations of haploid seed that satisfy the selection requirements for advancement to the next breeding cycle that are set by the user, all in the field and all within minutes of being harvested. These systems could be configured to transmit data to other locations, like a hand-held device near the harvester or more remote locales like an centralized processing and management center several miles away, such that the entire process could be monitored and controlled remotely. Similarly, it is envisioned that the entire process of harvesting, sorting, genotyping, and selection could be performed without a human operator in the field through the employment of automated vehicles, remote control and/or wireless communication.
[0037] This invention is not limited by the number of classes to which a given rapid haploid seed sorter can assign seeds. Rapid haploid seed sorters that can sort seeds into more than two classes are envisioned, which will provide users with more crossing and selection options in subsequent cycles of a breeding program, which can be leveraged to improve the efficiency of the breeding program and increase the rate of genetic gain.
[0038] Furthermore, Applicants do not intend that this invention should be limited to any specific crop species. Although some descriptions and examples use corn as a model crop, it is envisioned that concepts disclosed herein could be applied in any situation where a device is used to rapidly sort seed based on possession of a trait, including a trait associated with ploidy level, e.g. the high oil marker used to discriminate haploid vs. diploid seed in U.S. patent application Ser. No. 14/206,238.
[0039] As used herein, “germination” describes a point in a plant life cycle that begins when the first root radical emerges from the seed coat and can overlap “sprouting”, during which the seed begins to put out shoots, typically after a period of dormancy.
[0040] As used herein, “cultivate” describes any activity that promotes or improves the growth of a plant at any point in its life cycle, including germination.
[0041] Further areas of applicability of the present teachings will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present teachings.
EXAMPLES
Example 1
Mass Sorting Using a Rapid Haploid Seed Sorter
[0042] A user of this invention pollinates several thousand corn plants with a high-oil content inducer that reliably produces hybrid progeny seed containing 8% or greater oil content, e.g. UH601, and the putatively haploid seeds resulting from each induction cross are harvested several weeks later. Next, a sample from each population is obtained and then analyzed by a variety of techniques, including automated chipper genotyping (e.g. U.S. Pat. Nos. 7,611,842, 7,830,516, 7,685,768) and automated nucleotide sequencing, and the results analyzed statistically to detect and characterize the presence of potential quantitative trait loci (QTL) and/or informative nucleotide sequences in each population. Before concluding which populations actually meet the user's selection criteria, most or all of the several thousand populations are processed through the rapid haploid seed sorter described in U.S. patent application Ser. No. 14/206,238 to accumulate several thousand populations of pure haploid seeds, most of which do not meet the selection criteria set by the user. These populations of haploid seed that are substantially devoid of diploid seed can be stored using standard methods in the art that preserve seed viability for several days or weeks while the user continues to analyze the populations and determine which are most likely to contain the traits the breeder desires.
[0043] Realizing that all induction cross progeny populations are already haploid sorted, a user of this invention will be able to analyze their populations more thoroughly than attempting to process approximately the same number of haploid induction crosses using methods known in the art, which require one to stop analyzing earlier and make selections several weeks sooner in order to sort their selected populations in time for planting. Meanwhile, a user of this invention will have more time to analyze populations with objective tests that improve selection accuracy and reduce the likelihood of selecting false positives and/or eliminating false negatives from their DH pipeline as compared to those using methods currently known in the art. This will lead a user of this invention to experience greater efficiencies and reduce wasting resources on seeds that lack the frequency of desired traits.
Example 2
Late Sorting Using a Rapid Haploid Seed Sorter
[0044] A user of this invention pollinates several thousand corn plants with a high-oil content inducer that reliably produces hybrid progeny seed containing 8% or greater oil content, e.g. UH601, and the putatively haploid seeds resulting from each induction cross are harvested. Next, a sample from each population is obtained and analyzed with a variety of techniques, including automated chipper genotyping (e.g. U.S. Pat. Nos. 7,611,842, 7,830,516, 7,685,768) and automated nucleotide sequencing, and the results analyzed statistically to detect and characterize the presence of potential quantitative trait loci (QTL) and/or informative nucleotide sequences in each population.
[0045] The user of this invention will realize that a rapid haploid seed sorter such as that described in U.S. patent application Ser. No. 14/206,238 can sort approximately thirteen seeds per second, permitting the user to continue running tests and analyzing results that maximize selection accuracy until just a few hours before the planting deadline. Meanwhile, those using current DH production methods will be forced to cut short their tests, make their selections several weeks earlier, and will be unable to subject their populations to the same level of objective selection scrutiny. Thus, a user of this invention will be less likely to select false positives and/or eliminate false negative, leading to greater efficiencies and less resources wasted on seeds that lack the frequency of desired traits as compared to those using methods currently known in the art.
Example 3
Over Induction
[0046] A user of this invention calculates that their DH pipeline has the capacity to double a maximum 10,000 haploid progeny populations after they are harvested. Using current DH production protocols, the user could count on a selection accuracy of approximately 80%, meaning that doubling resources would be invested into approximately 2,000 populations that will be eliminated when later results reveal that those populations actually do not meet the selection criteria set by the user. On the other hand, by incorporating the methods of this invention, the user will realize that they will be able to free up the time and resources that would have been spent manually sorting seeds and will be able to use that time to improving selection decisions instead. By employing a rapid haploid seed sorter and performing highly-accurate selections among the induced haploid populations before doubling, a user of this invention can process significantly more induction crosses through their pipeline.
[0047] It is envisioned that a user in a typical growing season could perform a number of induction crosses that would significantly exceed the number of populations that are actually doubled. In some cases, the number of induced haploid progeny populations generated exceeds the number of populations that are doubled by about 10%, 20%, 30%, 40%, 50%%, 60%, 70%, 80%, 90%, 100%, 110%, 120%, 130%, 140%, 150%, 160%, 170%, 180%, 190%, 200% or any increment in between.
[0048] In other examples, the number of induction crosses performed would completely overwhelm the available doubling capacity of current DH pipelines. It is envisioned that a large breeding program would achieve better efficiency by generating a number of induced haploid progeny populations that exceeds the number of populations doubled in the pipeline by a factor of about 3×, 4×, 5×, 6×, 7×, 8×, 9×, 10× or any increment in between.
[0049] This enormous potential increase in the number of induced haploid populations that can be evaluated has the potential to revolutionize DH production throughput far above that which would be predicted directly from the increase in sorting speed afforded by a rapid haploid seed sorter. Aspects of this invention make feasible for the first time the ability to harvest, sort, and accurately select huge numbers of seed (e.g. hundreds of thousands, or several million, or more), or huge numbers of induced haploid populations (e.g. several thousand or more) in the same growing season.
Example 4
Concurrent Harvest Sorting
[0050] A corn harvester is configured to incorporate a rapid NMR haploid seed sorter. In addition to other ways the harvester processes seed, e.g. husking, shelling, etc., seeds are haploid sorted by the on-board rapid seed sorter while the harvester operates in the field. Although it may be necessary for the harvester to stop harvesting and/or traversing the field from time to time, the harvester is typically able to harvest a set number of seeds at approximately the same rate that the rapid seed sorter is able to analyze and sort the same set of seeds, such that there is essentially no point at which harvesting must be slowed or stopped to prevent an accumulation of harvested seeds waiting to be haploid sorted.
[0051] A user of this invention employing a machine configured in this way could harvest and sort the induced haploid populations of several thousand or even several hundred thousand, induction crosses growing in a field to obtain a population of pure haploid seed from each population. As the harvester traverses the field, on-board GPS-based computer systems cross reference the location of the harvester with the location of the populations in the field so that systems aboard the harvester can monitor and verify the population from which each seed moving through the harvester was harvested. Processing and packaging systems on board the harvester recombine the haploid seeds within each population to provide a series of containers, each containing a substantially homogeneous population of haploid seeds derived from a single induction cross, and labeled in a way that designates the germplasm of the parents used in that cross.
[0052] As soon as a population of haploid seeds has exited the harvester, a sample comprising at least one seed is captured and analyzed to determine whether the sample contains a trait at a frequency the user desires. The user continues to test samples of seeds from at least one of the harvested populations until a few days, or even a single day, or even a few hours before the user begins planting seeds from at least one of the harvested populations, at which point the user concludes their tests and selects the populations of haploid seeds that meet the selection criteria set by the user. Seeds from selected populations are germinated and subjected to doubling using standard methods of the art.
Example 5
Concurrent harvesting, sorting, and selection using a rapid haploid seed sorter.
[0053] A corn harvester is configured to incorporate a rapid NMR haploid seed sorter that operates on the principles described in U.S. patent application Ser. No. 14/206,238. The harvester is also configured to incorporate a rapid seed chipping and genotyping system based on the principles described in U.S. Pat. No. 7,830,516. The system is configured so that seeds are harvested and processed through the rapid haploid sorter and the chipping and genotyping system all at approximately the same rate, such that there is no backup of seed waiting to be processed at any step.
[0054] A user of this invention employing a combine configured in this way could harvest, sort, analyze, and select a population of seeds all substantially concurrently to obtain a population of pure haploid seed from each population, each satisfying both a phenotypic selection criterion set by the user, such as seed weight or water content (e.g. as measured by an on-board NMR sorter) and a genotypic selection criterion (e.g. as determined by the on-board genotyper). As the harvester traverses the field, on-board GPS-based computer systems cross references the location of the harvester with the location of the populations in the field so that systems aboard the harvester can monitor and verify the population and position from which each seed moving through the harvester was harvested. Processing and packaging systems on board the harvester recombine the haploid seeds within each population that satisfy the phenotypic and genotypic criteria set by the user to provide a series of containers, each containing a haploid population of seeds that is substantially devoid of diploid seeds and that has been derived from a single induction cross that satisfies the users selection criteria, and labeled in a way that designates the location in the field from which the seeds were harvested and the parents used in the cross that generated each seed.
[0055] Thus, the methods and systems disclosed herein reveal how a user can take full advantage of the improvements that incorporating a rapid haploid seed sorter into a DH pipeline makes available. Application of these concepts, and the alterations necessary to take full advantage of them, require counter-productive alterations in the way large DH pipelines using current or historic haploid sorting methods have been structured and managed for decades, and thus are not currently apparent to those of skill in the art.
[0056] The description herein is merely exemplary in nature and variations that do not depart from the gist of that which is described are intended to be within the scope of the teachings. Such variations are not to be regarded as a departure from the spirit and scope of the teachings.