Alfalfa Seed Characterization and Phytohormone Analysis

The alfalfa seed (Alfalfa cultivar ‘Zhongmu No. 3’) was provided by a specialized seed producer (Xintai Zhouquan Agricultural Technology Co., LTD, China). The similar size of healthy and plump seeds was screened and then sorted into three groups (brown, yellow and green) according to the seed coat color by visual inspection. The seed proportion was calculated by counting the number of seeds with different colors. Yellow seeds comprised the major part (59%) of the seed lot used for this study, while the relative amount of brown seeds was 33%. Green seeds comprised only 8% of the seed lot (Table 1). GA3, D-IAA, D-ABA, D-GA4 were purchased from OlChemIm Ltd. (Olomouc, Czech Republic). IAA was purchased from LGC Standards Ltd. (Tetdington, UK). ABA was purchased from Sigma-Aldrich (Merck, Germany).