DNA Replication And Several Other Methods Used For Seed Vigour Evaluation For Common Vetch

Seed vigour is an important index of seed quality and it's usually different for species.Common vetch?Vicia sativa?is an important legume which has great value in feeding animal,N fixation and conservation of water and soil,while there was little research about vigour testing methods of common vetch.In this study,eight commercial seed lots of common vetch were used.The seed vigour testing methods:accelerated aging,electric conductivity and germination rate,and the molecular method for DNA replication rate?4C/2C?of seeds were used to analyze the vigour,and to predict the field emergence of common vetch commercial seed lots,to provide scientific and technical basis for proposing the suitable vigour test methods for common vetch.The main results are as following.1.The standard germination of common vetch commercial seed lots were between 95%and 100%,and they can be divided into two groups with significant difference by multiple comparison.The vigour test methods:germination percentage of accelerated aging,electric conductivity,germination index and mean germination time can rank the seed lots into more groups than standard germination.For accelerated aging treatment,the germination percentage for combination of aging temperature?41,43,45??and time?6 treatments between 12-72 h?can rank seed lots into 3 to 7 groups for different treatments except for 45?-60 h and 45?-72 h.Electric conductivity,germination index and mean germination time were more sensitive in ranking seed lot quality than standard germination,which can divide the eight commercial seed lots into five groups.The results indicated that vigour is more sensitive in ranking seed lot quality than standard germination.2.In the study of DNA replication rate?4C/2C?analyzed by flow cytometry,LB01 nucleus isolation buffer was suitable for common vetch seeds among Galbraith,LB01,MG,Otto and Tris-MgCl₂.The time when DNA replication started earlier for high viability seeds?germination percentage is 96%?than low viability seeds?germination percentage is 51%?.4C/2C of seeds imbibed for 36 h and 48 h can rank the eight commercial seed lots into six and three groups with significant difference,which was more sensitive than standard germination.The results indicated that DNA replication rate has the potential for seed vigour testing.3.The correlation analysis of laboratory seed quality index and field emergence in two sites indicated that,there were no significant difference between standard germination and field emergence?P>0.05?,while significant difference presented between DNA replication rate,germination percentage of accelerated aging,electric conductivity and field emergence?P<0.05 or P<0.01?.They were DNA replication rate of seeds imbibed for 36 h?r=0.928,P<0.01?,germination percentage of accelerated aging 43?-24 h?r=0.861,P<0.01?,germination percentage of accelerated aging 41?-12 h and 43?-12 h?r=0.795,r=0.795,P<0.01?,DNA replication rate of seeds imbibed for 48 h?r=0.762,P<0.05?and electric conductivity?r=-0.750,P<0.05?for average correlation variation from high to low.We suggest that those six indexs can be used to predict field emergence of common vetch.4.DNA replication rate of seeds imbibed for 36 h and germination percentage of accelerated aging 43?-24 h was recommended for vigour testing of common vetch,for the sensitivity in ranking seed lot quality and predict field emergence than standard germination.