Study On Genetic Diversity Of 15 Oat Germplasm Materials

Oats are important forage and food crops.There are mainly two types of hulled oat(Avena sativa L.)and naked oat(Avena nuda L.).Naked oats are mainly used as grain crops.Hulled oats are used as winter spring forage for grazing livestock.In this study,15 oat germplasms were used as materials.Genetic diversity were identified and analyzed by phenotype and agronomic characters,drought resistance and GBS sequencing technology.The experiment research results were indicated as follows:15 oat germplasm resources were used,and their phenological period,growth period,phenotype and agronomic characters had been tested.The main phenotype and agronomic characters of 15 oats were measured by variance analysis,correlation analysis,principal component analysis and cluster analysis.The results show as follows: growth period of germplasm W3,W6,W11 is 90~100 d,W1,W2,W4,W5,W9 is 100~110 d,W8,W10,W12,W13,W14,W15 is more than 110 d,they belonging to precocious,medium and late ripening type,respectively.All of them can grow at local condition and reach seed maturation.Germplasm W14,W15 and W2 have better comprehensive agronomic characters,which can be used in the oat breeding of this region priority,W13 has the highest per plant yield,it has great potential of forage production.The per plant seed weight has significant positive correlation with the per plant seeds number and the per plant panicle number,the 1000-grain weight was positively correlated with seed length(p<0.01).The main components of 15 main characters were analyzed,and the cumulative contribution rate of five principal components was 85.57%.Based on the main agronomic characters,the 15 oat germplasm materials can be grouped into 5 types,and the clustering results have some correlation to the provenance of germplasm.Simulated drought stress conditions using different concentrations PEG-6000 for 15 oat germplasm materials.Seed germination rate,germination potential,germination index and vigor index were measured.The effects of drought stress on the length and weight of roots and shoots were studied.The growth trend graph of roots and buds was also shown.The relative germination percentage,relative germination potential,germination stress index,vigor drought resisting index,relative root length and relative shoot length were investigated.And comprehensive evaluate 15 oat germplasm materials by using the subordinate function method.The results indicated that the low content PEG-6000 improved seed germination and root growing.In contrast,different content PEG-6000 restrained shoot growing all the time.All the measured indexes were gradually restrained with higher concentrations of PEG-6000.The drought resistance of 15 oat germplasm materials was also different.According to the different indexes were measured,the oat germplasm materials with strong drought resistance were selected.The comprehensive drought resistances in the order of 15 oat germplasm materials was W8>W11>W1>W15>W2>W12>W5>W13>W6> W14>W10>W9>W4>W7>W3.Genotyping of 15 oat germplasm materials was carried out by using GBS sequencing technology.The results showed that the original data of sequencing was 255613544 reads.All the samples were filtered with high quality reads 127806772.The average number of reads per sample is about 8520451.15 oat germplasm materials received 887345 markers.The number of markers obtained by filtration was 446045.And the number of polymorphic markers of oat materials was 153702.The filter was identified by SNP,and 427482 SNP sites were identified,and the ratio of SNP to total mark was 96%.Group evolution analysis was carried out with filtered SNP.In system evolution analysis,the genetic differences between germplasm materials W4 and W7 were small.At the same time,the two kinds of germplasm materials showed the plants were short in the phenotype,the ability of the scion was poor and even the female was not pregnant.The genetic differences of three kinds of naked oat germplasm W12,W13 and W15 from China were relatively small,and they were first grouped together.Materials W5 and W9 are both from the United States.Their geographical distance is relatively close,the genetic relation is relatively close,and the clustering is one kind.Both W1 and W8 are from Canada and are grouped into the same category.GBS sequencing technology can accurately identify genetic differences and affinity of oat germplasm resources,which can be used as an important means for molecular identification of oat germplasm materials.In this paper,15 oat germplasm materials' genetic diversity was analyzed by phenotype and agronomic characters,drought resistance and GBS sequencing technology.It lays a foundation for the study of fine germplasm screening,hybrid parental selection and genetic breeding.It's great significance for the formulation of genetic diversity preservation measures of oat germplasm resources,the excavation of new gene of oat resources and the utilization of germplasm innovation to study molecular genetic diversity.