Evaluation Of 20 Onobrychis Viciaefolia Germplasm Resources

In order to screen out high-quality and high-yielding Onobrychis viciaefolia suitable for cultivation in Xinjiang and enrich the forage resources in the region,20 Onobrychis viciaefolia germplasm resources from home and abroad were collected in this study.By measuring the agronomic traits,yield and quality related indexes at different mowing periods,and using principal component analysis,cluster analysis and gray correlation analysis,the agronomic traits,yield and nutritional value of Onobrychis viciaefolia germplasm resources were evaluated.The study can provide a theoretical basis for the selection,promotion and cultivation of Onobrychis viciaefolia.The main findings are as follows.1.The coefficients of variation of 16 agronomic traits of 20 Onobrychis viciaefolia germplasm resources ranged from 5.75%to 73.78%,with the largest coefficient of variation for branch number and the smallest coefficient of variation for florets length.Except for leaf width,the Shannon-Wiener index of the other 15 characters was greater than 1.50.The cumulative contribution rate of the first eight principal components reached 64.640%,and the cumulative contribution rate of the first three principal components reached 31.881%.The 1st principal component can be used as the flower shape factor of Onobrychis viciaefolia,the 2nd principal component can be used as the leaf shape factor of Onobrychis viciaefolia,and the 3rd principal component can be used as the yield factor of Onobrychis viciaefolia.Three clusters were obtained by cluster analysis,of which clusterⅠcan be used as an excellent parent for breeding short and strong plant type,large and many flowers,clusterⅡcan be used as a genotype for with wide and many leaves,and clusterⅢcan be used as the germplasm with high plant type and large flowers.2.The yield of fresh grass and hay of the 20 Onobrychis viciaefolia germplasm resources were the best at the peak flowering stage,and the plant height,growth rate,dry to fresh ratio,leaf to stem ratio of fresh weight and dry weight were the best at the pod setting stage.At the peak flowering stage,S9 had the highest growth rate of 1.77 cm·d^-1,S15 had the highest fresh herbage yield of 32.67 t·hm^-2,and S3 had the highest dry herbage yield of 10.10 t·hm^-2.At the pod setting stage,S12 had the highest plant height of77.70 cm,S8 had the highest fresh weight leaf to stem ratio of 4.99,S20 had the highest dry weight leaf to stem ratio of 3.10,and S11 had the highest dry weight leaf to stem ratio of 3.10.By extracting the principal components,the yield indicators of different mowing periods could be converted into seven comprehensive indicators,with a cumulative contribution rate of 76.32%.Plant height at the early flowering stage had a strong loading of 0.661 in the first principal component,dry weight leaf to stem ratio at the pod setting stage had a strong loading of 0.688 in the second principal component,and hay yield at the early flowering stage had a strong loading of 0.564 in the third principal component.The best overall evaluation of S1 at the early flowering stage,S16 at the peak flowering stage and S14 at the pod setting stage.3.Crude protein content and relative feeding value of different Onobrychis viciaefolia germplasm resources were the best at the early flowering stage,and the contents of neutral detergent fiber,acid detergent fiber and tannin were the best at the peak flowering stage.At the early flowering stage,S16 had the highest crude protein content of 19.34%and S20 had the highest relative feeding value of 161.83%.At the peak flowering,S2 had the highest neutral detergent fiber of 60.08%,S6 had the highest acid detergent fiber of 40.79%,and S9 had the highest tannin content of 0.79%.The quality indicators of different mowing periods were converted into six composite indicators by principal component extraction,with a cumulative contribution of 83.39%.Among them,the relative feeding value at the peak flowering stage had a strong loading of 0.884 in the first principal component,the relative feeding value at the pod setting stage had a strong loading of 0.902 in the second principal component,crude protein at the early flowering stage had a strong loading of 0.671 in the third principal component.S6 at the early flowering stage,S6 at the peak flowering stage and S12 at the pod setting stage had the best overall evaluation.4.20 Onobrychis viciaefolia germplasm resources were ranked by equal weight correlation degree,S12 had the highest equal weight correlation of 0.8022 and was the best germplasm with comprehensive traits,followed by S13 and S18 with equal weight correlation of 0.7502 and 0.7458,respectively,S3 had the lowest equal weight correlation of 0.5609 and was poor with comprehensive traits.