Quantile regression in genomic selection for oligogenic traits in autogamous plants: A simulation study

This study assessed the efficiency of Genomic selection (GS) or genome‐wide selection (GWS), based on Regularized Quantile Regression (RQR), in the selection of genotypes to breed autogamous plant populations with oligogenic traits. To this end, simulated data of an F2 population were used, with traits with different heritability levels (0.10, 0.20 and 0.40), controlled by four genes. The generations were advanced (up to F6) at two selection intensities (10% and 20%). The genomic genetic value was computed by RQR for different quantiles (0.10, 0.50 and 0.90), and by the traditional GWS methods, specifically RR-BLUP and BLASSO. A second objective was to find the statistical methodology that allows the fastest fixation of favorable alleles. In general, the results of the RQR model were better than or equal to those of traditional GWS methodologies, achieving the fixation of favorable alleles in most of the evaluated scenarios. At a heritability level of 0.40 and a selection intensity of 10%, RQR (0.50) was the only methodology that fixed the alleles quickly, i.e., in the fourth generation. Thus, it was concluded that the application of RQR in plant breeding, to simulated autogamous plant populations with oligogenic traits, could reduce time and consequently costs, due to the reduction of selfing generations to fix alleles in the evaluated scenarios.

THE USE OF CLASSICAL AND MODERN METHODS IN RAPESEED (BRASSICA NAPUS) BREEDING AT VNIIMK

Introduction. Rapeseed is a facultative autogamous plant; its percentage of cross-pollination is 10–50%, so rapeseed breeding engages the line and population breeding methods as well as the development of hybrids and all innovative research approaches.Material and methods. Among the main techniques used for the development of parent material and, eventually, cultivars at the Pustovoit Institute (VNIIMK) is the pedigree method (individual selection from intraspecific and interspecific hybrid populations, combined with inbreeding). Physical and chemical mutagenesis is also employed in rapeseed breeding at VNIIMK. The material with yellow-colored seed coat has been obtained by exposing rapeseed seeds to various doses of gamma rays (50, 100 and 150 kR). Seed treatment with chemical mutagens is primarily aimed at changing the fatty acid composition of oil.Results. Breeding achievements for winter and spring rapeseed, registered by VNIIMK in the State Register of Breeding Achievements of the Russian Federation over the past 15 years, are highly productive line cultivars with a seed yield of 4–5 t/ha for winter rapeseed, and 2–3 t/ha for spring rapeseed. Promising experimental interline hybrids, significantly exceeding the reference in seed yield (by 1.61–2.26 t/ha), have been developed. Yellowseeded lines, which exceed the black-seeded reference cv. ‘Tavrion’ in seed yield by 0.08–0.15 t/ha, have been selected. We developed the material with an oleic acid level of 78.9– 80.5%.

The Possibility of Gene Flow Between Cultivated and Wild Rice in Ghana, A Review

Several transgenic rice lines have been developed and are currently under field trials around the world. There are future plans for the commercial release of transgenic rice into the environment. Rice is an autogamous plant and therefore not perceived to be a very high candidate for pollen mediated gene flow to wild and weedy relatives. However, in a tropical environment like Ghana, where sexually compatible wild Oryza species which belongs to the AA genome are present within the ecology of cultivated rice, the possibility of gene flow to wild species cannot be overlooked. There is little evidence on gene flow and its consequences on the wild rice species should they acquire useful genes through gene flow. This review discusses the chances of cultivated to wild rice gene flow in Ghana and the biosafety considerations that should be put in place before the commercial release of genetically modified (GM) rice.

Genetic characterization of Spanish lentil landraces (Lens culinaris Medik.) by biochemical markers

Diversity analysis and a genetic structure study of 25 lentil landraces (<italic>Lens culinaris</italic> Medik.) from the northern east part of the Iberian Peninsula were carried out. 8 isozymes: PGI, PRX, LAP, 6PGD, GOT, SKDH, PGM and ME, have been used for this purpose having found 17 loci for them, with 52.94% polymorphic loci and a total amount of 21 alleles. All populations show between 18 and 26 alleles. Genetic distance (D) was 0.123. Diversity parameters show similar or higher levels compared to other autogamous plant populations. They show an heterozygote defect. Coefficient of homozygotes among populations (G_ST) value 0.414, was similar to Inbreeding coefficient among populations (F_ST) that was 0.454. Main component analysis showed that the most important isozymes in the characterization process were GOT-3 and PGM-2. Four groups of populations were obtained by cluster analysis. This information reveals new data for improving their use in the germplasm banks for crop programs.