Evaluation Of Tibet Cultivation And Wild Tartary Buckwheat Resources And The Phylogeny Based On Molecular Markers

As one of the origins of genus Fagopyrum,Tibet has a special environment and diverse climate and extremely rich germplasm resources of Tartary buckwheat.However,there are few reports on the germplasm of Tartary buckwheat native to Tibet.This study collected 140 wild and cultivated Tartary buckwheat germplasm resources through field investigations,and cultivated them under the same environmental conditions with 35 Tartary buckwheat germplasms from other regions as control.The genetic variation and systematic relationship on Tibet Tartary buckwheat germplasms were studied by 13 agronomic traits including fruit number per plant（FN）,fruit weight per plant（FW）,1000 fruit weight（1000FW）,fruit area（FA）,fruit perimeter（FP）,width and length ratio（L/W）,fruit length（FL）,fruit width（FWI）,fruit diameter（FD）,growth period（GP）,plant height（PH）,branch number of main stem（BN）,node number of main stem（NN）,and 6 quality indicators including albumin content（ALB）,globulin content（GLO）,gliadin content（GLI）,glutenin content（GLU）,crude protein（CP）,total flavonoids content（TF）,and SSR molecular markers.The main results were as follows:1.Collection and Conservation of Germplasm ResourcesThrough field investigations in Tibet,140 accessions of Tartary buckwheat germplasm resources were collected in southeastern Tibet,including 131 accessions of wild Tartary buckwheat and 9 accessions of cultivated Tartary buckwheat.All germplasms are saved up in germplasm pool of the Research Center of Buckwheat Industry Technology,Guizhou Normal University at-20℃.123 wild Tartary buckwheat germplasms were successfully expanded,providing a material basis for future buckwheat genetic breeding research.2.Evaluation of Germplasm Resources167 Tartary buckwheat germplasms including 123 wild Tartary buckwheat native to Tibet（WTT）,9 cultivated Tartary buckwheat native to Tibet（CTT）,and 35 cultivated Tartary buckwheat native to beyond Tibet（CTBT）were evaluated by 13 agronomic and quality traits.In terms of agronomic traits,the variation coefficients of FN（CV=74.54%,（?）=179.88 fruits）and FW（CV=84.91%,（?）=3.37 g）are larger.WTT on FN（CV=85.00%,（?）=151.56 fruits）,FW（CV=102.31%,（?）=2.74 g）,1000FW（CV=16.42%,（?）=17.02 g）,FA（CV=13.57%,（?）=10.40 mm²）,FP（CV=9.08%,（?）=13.53 mm）,L/W（CV=13.51%,（?）=1.46）,FL（CV=9.30%,（?）=4.62 mm）,FD（CV=7.15%,（?）=3.60 mm）,PH（CV=36.47%,（?）=41.35 cm）,BN（CV=15.57%,（?）=5.10）,and NN（CV=22.53%,（?）=9.37）has higher variation coefficients and lower average than CTT and CTBT.And WTT has earlier maturity with the average GP（66.29 d）significantly lower than CTT（75.11 d）and CTBT（73.49 d）.In terms of quality traits,WTT has higher coefficient of variation on GLO(CV=32.91%,（?）=10.17 mg·g^-1),GLU(CV=26.89%,（?）=159.23 mg·g^-1),GLU(CV=10.73%,（?）=41.18 mg·g^-1)than that of CTT and CTBT,and significantly higher average of CP(159.23 mg·g^-1)than CTT(144.55 mg·g^-1)and CTBT(125.72 mg·g^-1),indicating high protein characteristics.Correlation analysis results show that there are different degrees of simple correlation among traits such as FN,FW,1000FW,PH,CP and other important traits.The results of principal component analysis showed that 19 traits of 119 Tartary buckwheat germplasm could be converted into 4 principal components,namely plant type factor,fruit type factor,quality factor,and composite factor.Based on the constructed principal component comprehensive model,the good germplasms such as Zhongxun Tartary,Tangwang Tartary,Fugong Tartary,Luohe Tartary,Liangku-4,Tibet-270,Tibet-216,Tibet-79,Tibet-74,and Tibet-282 were selected.Hierarchical cluster analysis showed that there are 19 accessions with large-FP（（?）=15.03 mm）and high CP(（?）=172.12 mg·g^-1),20 accessions with high TF(（?）=24.45 mg·g^-1),and 17 accessions with low GP（（?）=64.29 d）.Among these 56 accessions of Tartary buckwheat germplasm,53 accessions are WTT,and 3accessions are CTBT.3.Genetic Diversity of Tartary buckwheat Germplasm Based on SSR StudyA total of 185 alleles were amplified by 53 pairs of primers in 175materials,with an average of 3.49 alleles and 1.82 effective alleles per locus;The distribution range of Shannon Information Index was 0.02～1.07,the mean is 0.63;The distribution range of the observed heterozygosity is 0.00～1.00,with an average value of 0.63;The expected heterozygosity distribution range is 0.01～0.65,with an average value of0.42;The distribution range of the polymorphism information content is0.11～0.72,with an average value of 0.33.The genetic similarity coefficients of 175 Tartary buckwheat germplasms vary from 0.5934 to0.9918,with an average value of 0.7793,indicating that the genetic variation of Tartary buckwheat germplasms in this study is rich.4.Correlation between SSR markers and traitsA total of 148 markers were detected to have significant associations with 19 traits.Among them,the important traits and the number of their markers are as follows:FN with 17;FW with 18;1000FW with11;GP with 16;PH with 42;CP with 42;TF with 35.There are 30 markers associated with two or more important traits at the same time,namely Tat G003-363,Tat G118-354,Tat G118-393,Tat G121-400,Tat G141-296,Tat G141-334,Tat G142-418,Tat G162-130,Tat G169-149,Tat G187-252,Tat G187-268,Tat G187-276,Tat G187-292,Tat G187-322,Tat G187-390,Tat G187-420,Tat G217-457,Tat G218-475,Tat G231-403,Tat G232-196,Tat G232-206,Tat G232-278,Tat G255-250,Tat G259-246,Tat G265-279,Tat G265-291,Tat G272-186,Tat G272-196,Tat G272-221,Tat G272-236.These markers can be used in the breeding of Tartary buckwheat.