Progress 01/09/14 to 09/30/18
Outputs
Target Audience:Wheat geneticists and breeders Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Graduate student Chad Jorgensen participated in the development of introgression lines and evaluation of salt-tolerance. He has graduated with a doctorate degree with specialization in plant breeding. Graduate student (plant breeding) Jiale Xu is responsible for genotyping and phenotyping of the introgression lines. He was also the lead worker in development of statistical tools for QTLs meta-analyses in wheat. The graduate student Juliya Abbasi (plant breeding) is developing materials for the study of genetic basis of the perennial growth habit and salt-stress tolerance in wheatgrasses and wheat x wheatgrass amphiploids. Postdoctoral trainee Hao Li was the lead worker in introgression of Su1-Ph1, the epistatic suppressor of the wheat Ph1 gene, from Aegilops speltoides to bread and durum wheat and the characterization of material. He has completed the project and has accepted an academic position in China. How have the results been disseminated to communities of interest?Publication and conference presentations What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Impact of the project Salinity is a serious environmental hazard for irrigated agriculture in the American west and agriculture in semiarid areas of the world. Wheatgrasses are close relatives of wheat with which they can be hybridized. They are perennial and naturally grow in salt marshes. Previous studies showed that wheatgrass salinity tolerance and perennial growth are expressed in wheatgrass x wheat hybrids and from them derived amphiploids (stable genetic stocks derived from interspecific hybrids). Wheatgrasses provide means to discover genes that control salinity tolerance and perennial growth. We reason that germplasm with these genes can be used for the improvement of salt-tolerance in wheat and for the development of perennial forage grasses that can be irrigated with substandard or drainage water, which is almost always saline, in California and other western states. Following this rationale, we developed 23 wheat x wheatgrass amphiploids for analyses and manipulation of salinity tolerance and perennial growth habit in wheat. We also developed a large population of 556 lines from a wheat x wheatgrass hybridization to incorporate salinity tolerance and perennial growth into wheat. We developed marker for genetic mapping of these lines and showed that 131 of them contained wheatgrass germplasm. In a separate project, we discovered a gene in one of the wild relatives of wheat that overrides the expression of wheat genes regulating meiotic recombination of chromosomes and facilitates recombination of wheat chromosomes with the chromosomes of wild relatives of wheat, including wheatgrasses. We incorporated the gene into bread and durum wheat for non-GMO incorporation of economically important genes, such as those controlling salinity tolerance and perennial growth, from wheat relatives, including wheatgrasses, into wheat. Objective 1. Develop salt-tolerant wheat x wheatgrass germplasm 1.2 Genetic improvement of octoploid amphiploids The decaploid amphiploid from hybridization Chinese Spring wheat x allotetraploid L. scrirpeum (LsCS, genome formula AABBDDE1E1E2E2) was crossed with a high yielding, large seeded wheat line and the resulting octoploid hybrid (AABBDDE1E2) was self-pollinated. Chromosome numbers in progeny varied due to poor meiotic chromosome pairing between the L. scirpeum E1 and E2 genomes. We have obtained plants with chromosome numbers approaching the octoploid euploid number (2n=56). Some initially showed superior agronomic attributes relative to the primary octoploid amphiploids, such as AgCS, but their productivity declined upon selfing and none appeared agronomically useful after three generations of self-pollination. Objective 2. Develop perennial salt-tolerant forages Previous studies in rice, sorghum and wheatgrasses suggested that genes for the perennial growth habit are located on wheatgrass chromosomes 2E and 4E. To map these genes, we selected 17 and 16 introgression lines involving chromosomes 2E and 4E, respectively, from the introgression population described in section 1.1. They are currently evaluated for perennial growth habit by measuring their ability to re-grow after senescence and removal of the straw. Two trials were performed to evaluate the productivity and perennial growth habit of the wheat-Lophopyrum amphiploids in the field. In November 2016 through June 2017, we included two 56-chromosome amphiploids, T. aestivum cv Chinese spring (CS) x L. elongatum collected in Tunisia (AgCS) and CS x L. elongatum collected in Corsica (CSLe), for forage production in comparison with eight other wheat, barley, oat, or triticale forage lines. AgCS ranked first of the 10 lines for forage fresh weight at the end of the growing season, while CSLe was eighth. In the second trial we evaluated perennial growth. Lines had been started and maintained in the greenhouse and then transplanted to the field. Included in the trial were: common wheat, five octoploid amphiploid lines, two decaploid amphiploid lines, and two tetradecaploid amphiploid lines. Parental lines were Chinese Spring wheat (hexaploid) and diploid, tetraploid, octoploid (L. turcicum), and decaploid (L. ponticum) tall wheatgrasses. Plants were periodically cut and fresh biomass was recorded. The wheat plants and most of the octoploid amphiploids did not survive into the second season. In the third year only wheatgrasses and tetradecaploid amphiploids derived from octoploid L. turcicum and decaploid L. ponticum were alive. We concluded that the perennial growth habit is insufficiently expressed in the octoploid and decaploid amphiploids. We are currently evaluating salinity tolerance of the tetradecaploid amphiploids derived from octoploid L. turcicum and decaploid L. ponticum. Preliminary tests showed that these amphiploids are highly salt-tolerant. They are perennial, vigorous, and salt-tolerant. Unfortunately, they are not fertile. To be of a practical significance for forage production in salinized soils, technology for vegetative reproduction of these plants would have to be developed. Objective 3. Genetic markers for genetics and breeding of wheatgrass and wheat x wheatgrass amphiploids We developed 97 wheatgrass genome-specific single nucleotide polymorphism (SNP) markers located in genes and covering the entire L. elongatum genome. We used them to genotype the entire population of introgression lines in objective 1.1. We identified 131 introgression lines harboring L. elongatum germplasm among the 556 introgression lines. With these markers, we identified two introgression lines among 13 lines involving L. elongatum chromosomes 7E that are highly resistant to fusarium head blight. We also developed statistical tools for comparative genetics and meta-analysis of quantitative trait loci (QTLs). We summarized 585 QTLs, including those affecting genetic tolerance to salt stress, reported in the literature and subjected them to meta-analysis with these statistical tools to find their locations.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2017
Citation:
Li H., Deal K.R., Luo M.-C., Ji W.Q., Distelfeld A., and J. Dvorak (2017) Introgression of the Aegilops speltoides Su1-Ph1 Suppressor into Wheat. Frontiers in Plant Science 8 art 2163
- Type:
Journal Articles
Status:
Accepted
Year Published:
2019
Citation:
Xu J., Dai X., Ramasamy R.K., Wang L., Zhu T., McGuire P.E., Jorgensen C.M., Dehghani H., Gulick P.J., Luo M.-C., M�ller H.G., and J. Dvorak (2019) Aegilops tauschii genome sequence: A framework for meta-analysis of wheat QTLs. G3, doi.org/10.1534/g3.118.200921.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2019
Citation:
Abbasi, J., McGuire P.E., and J. Dvorak (2019) Expression of perennial growth habit and salt-stress tolerance in wheat x wheatgrass amphiploids depends on the dose of wheatgrass genomes. Plant and Animal Genome 27, Abstract PE1014
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Progress 10/01/16 to 09/30/17
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Graduate student Chad Jorgensen who participated in the development of the plant materials and evaluation of salt tolerance graduated with a doctorate degree with specialization in plant breeding. Graduate student Jiale Xu is responsible for genotyping an phenotyping of the materials. A graduate student Julia Abbasi has passed her qualifying examination and is now responsible for the development of materials for study of the genetic basis of the perennial growth habit of the wheat x wheatgrass amphiploids How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?Objective 1. We will develop a genome-wide L. elongatum-genome specific markers and will genotype the entire set of 613 introgression lines to detect the presence of recombined chromosomes harboring L. elogatum chromosome segments. We will continue self-pollination of progeny from hybridization LsCS x hexaploid wheat focusing on 56-chromosome plants. We will contine evaluating the cytogenetic stability of backcrosses of /CS x 4x L. elongatum/ x T. aestivum. Objective 2. We will complete the perenniality assessment trial for the amphiploids and will complete mapping the perenniality gene on L. elongatum chromosome 4E.
Impacts
What was accomplished under these goals?
Objective 1. 1.1 Development of hexaploid Lophopyrum x wheat derivatives We crossed an octopoloid amphiploid T. aestivum cv Chinese Spring x diploid L. elongatum (genomes EE) collected in Tunisia (AgCS, genome formula AABBDDEE) with the Chinese Spring ph1b deletion line. To remove the Ph1 gene and facilitate recombination between Lophopyrum and wheat homoeologous chromosomes, we crossed the hybrid with a durum (T. turgidum ssp durum, genomes AABB) ph1 deletion mutant (ph1c), and plants homozygous for ph1 were selected using molecular markers. These plants had the complete set of the wheat A and B genome chromosomes but variable numbers of the D- and E-genome chromosomes. We then backcrossed them into ph1b and self-pollinated about 970 F2 plants. In the 2015-2016 season we completed self-pollination and produced 613 F6 lines. In the 2016-2017 season, we completed a two-year evaluation of salt tolerance of a subset of 103 of these lines in Pakistan in fields irrigated with fresh water (control) or saline water (medium and high salinity). Five of the 103 lines had greater grain yield than the check variety Pasban-90 by 20 to 30%. Three of these five lines showed also increased salinity tolerance, as their grain yield was less reduced in salinized plots compared to the control fields than that of Pasban-90 in both years. These are very encouraging results suggesting that the population of 613 introgression lines harbors productive lines with high levels of salt tolerance. We developed 96 genome-specific single nucleotide polymorphism (SNP) markers located in L. elongatum genes covering the entire L. elongatum genome and genotyped a population of 468 with SNP markers on L. elongatum chromosomes 4E and 7E. A total of 15 and 14 introgression lines (3% each) harbored a recombined chromosome 4E and 7E, respectively. We selected 13 of the 14 7E introgression lines to evaluate resistance to fusarium head blight, which can be a serious disease in humid areas of the world. Three introgression lines, one with the entire short arm and two with the entire long arm were highly resistant to fusarium head blight. 1.2 Genetic improvement of octoploid amphiploids The decaploid amphiploid from hybridization Chinese Spring wheat x allotetraploid L. scrirpeum (LsCS, genome formula AABBDDE1E1E2E2) was crossed with a high yielding, large seeded wheat line and the resulting octoploid hybrid (AABBDDE1E2) was self-pollinated. Chromosome numbers of progeny varied due to poor meiotic chromosome pairing between the L. scirpeum E1 and E2 genomes. We have obtained plants with chromosome numbers approaching the octoploid euploid number (2n=56). Some show superior agronomic attributes relative to the primary octoploid amphiploids, such as AgCS. To avoid the aneuploid bottleneck in this breeding strategy, we developed a decaploid amphiploid AeCS from hybridization of Chinese Spring wheat with autotetraploid L. elongatum (genome formula AABBDDEEEE). We produced 56-chromosome lines from all of the above crosses and are currently investigating their cytogenetic behavior. Objective 2. We developed a set of amphiploids with increased dose of individual wheatgrass chromosomes for the study of the genetics basis of perennial growth habit in wheatgrasses. We hypothesized that the expression of the perennial growth habit, salt tolerance, fusarium head blight resistance, and other quantitatively inherited and agronomically important traits can be increased in the octoploid wheat x wheatgrass (L. elongatum) amphiploids by increasing the dose of L. elongatum chromosomes harboring genes critical for their expression in the L. elongatum genome. The development of such unique plants was made possible by the existence of wheat x wheatgrass disomic substitution (DS) lines we developed earlier. In a DS line, a specific pair of wheat chromosomes, e.g. 1D, was replaced by a pair of homoeologous (=related) chromosomes of L. elongatum, in this case 1E. This DS line is hence called DS1E(1D). We earlier developed seven such DS lines, one for each of the wheat D-genome chromosomes: DS1E(1D), DS2E(2D)...DS7E(7D). We have succeeded producing five of the seven possible amphiploids from crossing DS lines with L. haifense. We have so far failed to produce amphiploids DS2E(2D) x L. haifense and DS4E(4D) x L. haifense. To map the locus that controls perennial growth habit, DS4E(4D) was crossed with ph1b and F1 was backcrossed to ph1b. A total of 15 plants homozygous for ph1b and having 42 chromosomes was obtained. They are being screened for a 4E-4D double monosomy to identify those that are double monosomics. Two trials were performed to evaluate the productivity and perenniality of the wheat-Lophopyrum amphiploids. In November 2016 through June 2017, we included two 56-chromosome amphiploids, T. aestivum cv Chinese spring (CS) x L. elongatum collected in Tunisia (AgCS) and CS x L. elongatum collected in Corsica (CSLe), for forage production in comparison with eight other wheat, barley, oat, or triticale forage lines. AgCS ranked first of the 10 lines for forage fresh weight at the end of the growing season, while the amphiploid, CSLe, was eighth. In the second trial we evaluated perenniality. Lines had been started and maintained in greenhouse conditions and then transplanted to the field. Included in the trial were: common wheat, five octoploid amphiploid lines, two decaploid amphiploid lines, and two tetradecaploid amphiploid lines. Parental lines were Chinese Spring wheat (hexaploid) and diploid, tetraploid, octoploid, and decaploid tall wheatgrasses. Plants were periodically cut and fresh biomass was recorded. The wheat plants and most of the octoploid amphiploids did not survive into a second season but the amphiploids and the wheatgrass parents are growing.
Publications
|
Progress 10/01/15 to 09/30/16
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Graduate student Chad Jorgensen continued participation in the development of the plant materials and evaluation of salt tolerance. Graduate student Jiale Xu has passed the qualifiying exam and is now responsible for the development and evaluation of the materials. A graduate student Julia Abbasi joined the project and is responsible for the development of materials for study of the genetic basis of the perennial growth habit of the wheat x wheatgrass amphiploids. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?Objective 1. 1.1. We will increase seed of the 613 F6 lines in the greenhouse and plant then for further increase at the filed Tule Lake station in the April of 2017. 1.2. We will continue self-pollination of progeny from hybridization LsCS x hexaploid wheat focusing on 56-chromosome plants. The progeny from the cross of the decaploid amphiploid AeCS with high-yielding lines of T. aestivum will be advanced in the greenhouse. Objective 2. We will generate new perennial trials of the amphiploids .
Impacts
What was accomplished under these goals?
Objective 1. 1.1 Development of hexaploid Lophopyrum x wheat derivatives We crossed an octopoloid amphiploid T. aestivum cv Chinese Spring x diploid L. elongatum (genomes EE) collected in Tunisia (AgCS, genome formula AABBDDEE) with the Chinese Spring ph1b deletion line. To remove the Ph1 gene and facilitate recombination between Lophopyrum and wheat homoeologous chromosomes, we crossed the hybrid with a durum (T. turgidum ssp durum, genomes AABB) ph1 deletion mutant (ph1c), and plants homozygous for ph1 were selected using molecular markers. These plants had the complete set of the wheat A and B genome chromosomes but variable numbers of the D- and E-genome chromosomes. We then backcrossed them into ph1b and self-pollinated about 970 F2 plants. In the 2015-2016 season we completed self-pollination and produced 613 F6 lines. 1.2 Genetic improvement of octoploid amphiploids The decaploid amphiploid from hybridization Chinese Spring wheat x allotetraploid L. scrirpeum (LsCS, genome formula AABBDDE1E1E2E2) was crossed with a high yielding, large seeded wheat line and the resulting octoploid hybrid (AABBDDE1E2) was self-pollinated. Chromosome numbers of progeny varied due to poor meiotic chromosome pairing between the L. scirpeum E1 and E2 genomes. We have obtained plants with chromosome numbers approaching the octoploid euploid number (2n=56). Some show superior agronomic attributes relative to the primary octoploid amphiploids, such as AgCS. To avoid the aneuploid bottleneck in this breeding strategy, we developed a decaploid amphiploid AeCS from hybridization of Chinese Spring wheat with autotetraploid L. elongatum (genome formula AABBDDEEEE). In AeCS, the E genomes are identical and we expect regular bivalent pairing and hence auploid progeny in the octoploid AeCS x hexaploid wheat hybrids. We produced 56-chromosome lines from all of the above crosses are currently evaluated in the field at UC Davis. Objective 2. To assess the perennial growth habit of the octoploid amphiploids, a replicated trial of AgCS, BeCS (octoploid amphiploid Chinese Spring x Th. bessarabicum), and control Chinese Spring wheat were planted in the fall of 2014 in Davis. Hay was harvests in the winter and spring of 2015. The plots were fertilized and irrigated in September, 2015 and let regrow for the 2015-2016 season. The growth in the second year was very good and the trial looked very promising. Unfortunately, a worker accidentally sprayed all our plots with herbicide and destroyed the trial. We developed a set of amphiploids with increased dose of individual wheatgrass chromosomes for the study of the genetics basis of of perennial growth habit in wheatgrasses. We hypothesized that the expression of the perennial growth habit, salt tolerance, fusarium head blight resistance, and other quantitatively inherited and agronomically important traits can be increased in the octoploid wheat x wheatgrass (L. elongatum) amphiploids by increasing the dose of L. elongatum chromosomes harboring genes critical for their expression in the L. elongatum genome. The development of such unique plants was made possible by the existence of wheat x wheatgrass disomic substitution (DS) lines we developed earlier. In a DS line, a specific pair of wheat chromosomes, e.g. 1D, was replaced by a pair of homoeologous (=related) chromosomes of L. elongatum, in this case 1E. This DS line is hence called DS1E(1D). We earlier developed seven such DS lines, one for each of the wheat D-genome chromosomes: DS1E(1D), DS2E(2D)...DS7E(7D). Each of the seven DS lines was crossed with L. haifense accession #31 collected in Israel, hybrid embryos were rescued, the hybrids were treated with colchicine, and an octoploid amphiploid line was developed. Normally, a wheat x wheatgrass amphiploid has seven pairs of wheatgrass chromosomes. In contrast, in these amphiploids one specific wheatgrass chromosome pair is in a doubled dose, there are two such chromosome pairs, one is replacing the wheat homoeologous D-genome chromosome pair. Thus, in amphiploid 1E(1D)*Lhaifense, there are four chromosomes 1E, in amphiploid 2E(2D)*Lhaifense there are four chromosomes 2E, etc. Genes that reside on the chromosome with the doubled dose are expected to be overexpressed.
Publications
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Progress 10/01/14 to 09/30/15
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Graduate student Chad Jorgensen participated in the development of the plant materials and evaluation of salt tolerance of the germplasm. Graduate student Jiale Xu was accepted and became responsible for the development of hexaploid backross materials. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?Objective 1. 1.1. We will continue self-pollination of the hexaploid backross families. Each family will be planted in November, 2015 in a salinized field at UC Davis to assess their salt tolerance. We will increase seed of LhCS at the Tule Lake station for the evaluation of salt tolerance in the 2016-2017 season. 1.2. We will continue self-pollination of progeny from hybridization LsCS x hexaploid wheat. Plants with 56 chromosomes and good fertility will be selected. The decaploid amphiploid AeCS will be crossed with high-yielding lines of T. aestivum and the resulting 56-chromosome hybrid will be included into the octoploid gene pool for breeding. Objective 2. We will continue the perennial trials of AgCS and BeCS. We will harvest hay and grain from the perennial plots and determine yields.
Impacts
What was accomplished under these goals?
1.1 Development of hexaploid Lophopyrum x wheat derivatives We crossed an octopoloid amphiploid T. aestivum cv Chinese Spring x diploid L. elongatum (genomes EE) collected in Tunisia (AgCS, genome formula AABBDDEE) with the Chinese Spring ph1b deletion line. To remove the Ph1 gene and facilitate recombination between Lophopyrum and wheat homoeologous chromosomes, we crossed the hybrid with a durum (T. turgidum ssp durum, genomes AABB) ph1 deletion mutant (ph1c), and plants homozygous for ph1 were selected using molecular markers. These plants had the complete set of the wheat A and B genome chromosomes but variable numbers of the D- and E-genome chromosomes. We then backcrossed them into ph1b. A total 970 of these lines were self-pollinated for two generations. We will continue self-pollination of this material for two more generations. Each family was planted in April, 2015 at the Tule Lake Station in Northern California to generate seeds for preliminary field trial of salt tolerance of these families. 1.2 Genetic improvement of octoploid amphiploids The decaploid amphiploid from hybridization Chinese Spring wheat x allotetraploid L. scrirpeum (LsCS, genome formula AABBDDE1E1E2E2) was crossed with a high yielding, large seeded wheat line and the resulting octoploid hybrid (AABBDDE1E2) was self-pollinated. Chromosome numbers of progeny varied due to poor meiotic chromosome pairing between the L. scirpeum E1 and E2 genomes. We have obtained plants with chromosome numbers approaching the octoploid euploid number (2n=56). Some show superior agronomic attributes relative to the primary octoploid amphiploids, such as AgCS. To avoid the aneuploid bottleneck in this breeding strategy, we developed a decaploid amphiploid AeCS from hybridization of Chinese Spring wheat with autotetraploid L. elongatum (genome formula AABBDDEEEE). In AeCS, the E genomes are identical and we expect regular bivalent pairing and hence auploid progeny in the octoploid AeCS x hexaploid wheat hybrids. Objective 2. To assess the perennial growth habit of the octoploid amphiploids, a replicated trial of AgCS, BeCS (octoploid amphiploid Chinese Spring x Th. bessarabicum), and control Chinese Spring wheat were planted in the fall of 2014 in Davis. Hay was harvests in the winter and spring of 2015. The plots were fertilized and irrigated in September, 2015 and let regrow for the 2015-2016 season.
Publications
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Progress 01/09/14 to 09/30/14
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? Graduate student Chad Jorgensen participated in the development of the plant materials and evaluation of salt tolerance of the initial germplasm. Undergraduate student Catherine Curley was trained in setting up solution culture experiments, their maintenance, data collection and analyses. Postdoctoral trainee Yong Zhong was trained in interspecific hybridization and embryo rescue. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals? Objective 1. We will continue self-pollinating the 970 backcross lines. Objective 2. We will cross the decaploid tritipyrum we developed with several hexaploid wheat cultivars and study chromosome behavior in subsequent generations to evaluate the possibility of producing a stable octoploid tritipyrums in various hexaploid wheat genetic backgrounds. We will produce additional decaploid tritipyrums from hybridization of hexaploid wheat cultivars with tetraploid Lophopyrum.
Impacts
What was accomplished under these goals?
Objective 1. Development of hexaploid tritipyrum We crossed the existing octopoloid tritipyrum (AgCS) (Triticum aestivum `Chinese Spring' genomes AABBDD x Lophopyrum elongatum, accession D) with the genome formula AABBDDEE with the Chinese Spring ph1b deletion line. To obtained hybrids were had to rescue the embryos in tissue culture. To remove the Ph1 gene and facilitate recombination between wheatgrass and wheat homoeologous chromosomes, we crossed the hybrids with the durum (T. turgidum ssp durum, genomes AABB) deletion mutant ph1c, and plants homozygous for the ph1 state were selected using molecular markers for the deletions, which we also developed. These plants had the complete set of the wheat A and B genome chromosomes but variable numbers of the wheat D-genome chromosomes and the E-genome chromosomes. We then either backcrossed these plants into the ph1b stock or to Chinese Spring. A total 970 of these lines were self-pollinated for one generation. We plan to continue self-pollination of this material for three more generations. We will then assess salt tolerance and perennial growth habit in the resulting backcross recombinant inbred lines (BRILs) and map the quantitative trait loci (QTLs) for these two traits. Objective 2. Development of octoploid tritipyrum We previously collected a new, salt-tolerant accession (e4) of diploid L. elongatum (genomes EE) on the Mediterranean island of Corsica. We crossed the accession as a male with hexaploid bread wheat T. aestivum Chinese Spring, rescued hybrid embryos, and developed a new octoploid amphiploid tritipyrum with 2n=8x=56 (genomes AABBDDEE) by treating the hybrid with 0.2% solution of colchicine. We also crossed a salt-tolerant accession of tetrapoloid L. scirpeum (genomes E1E1E2E2) as a male with Chinese Spring, rescued hybrid embryos, and developed a new decaploid amphiploid tritipyrum with 2n=10x=70 (genome formula AABBDDE1E1E2E2) by treating the tetraploid hybrid (genomes ABDE1E2) with 2% solution of colchicine. In the next phase of the project we will assess salt tolerance of these amphiploids and if they are tolerant, we will use them as new sources of salt-tolerant germplasm in breeding octoploid salt tolerant forages for California.
Publications
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