The relationship between heat-tolerance and fall dormancy of Medicago sativa cultivars at seed germination stage
To explore the influence of heat stress on the seed germination of Medicago sativa cultivars with different fall dormancy, five germination characteristics (germination rate, germination index, vigor index, fresh weight of radicle and germinability) have been tested to evaluate the thermotolerance of alfalfa eultivars with 14 different fall dormancy during germination stage. Using covariance,the membership functions and cluster analy sis,the results showed that the thermotolerance of different cuhivars was significantly different at seed germina- tion stage under heat stress. "Sardil0",a high fall dormancy cultivar,has the strongest heat tolerance,with high est germination index, vigor index, fresh weight of radicle, germinability and germination rate as 67.78,66.70,0. 98 g,99.33% and 92.89~ respectively. Cluster analysis divided these 14 cultivars into three thermotolerance categories : cultivars with highest thermotolerance, including "Biaogan','WL903','1075", and "Sanditi'; cultivars with the lowest thermotolerance,including "Sardi10"and'Sequel',and 'Power','Hunter River" and "Algonquin'. The other are cultivars have medium thermotolerance. Non-fall dormancy cultivars showed stronger thermotolerance at the stage of germination than fall dormancy cultivars. The vigor index was an effective thermotolerance index of alfalfa at seed germination stage in this study.
NETL
NSTL
万方数据
维普
