小麦收获前穗发芽的生理生化特性研究

1984-1986年两个生长季节，先后研究了41个小麦品种（系）收获前穗发芽的生理生化特性。研究结果表明，供试品种（系）的穗发芽抗性有显著的差异。穗上发芽率与α-淀粉酶活性、降落值、籽粒吸水6、12、24小时的电导率和呼吸强度、籽粒吸水速率等的相关较高，与内源ABA含量之间的相关较低，以上这些性状除内源ABA含量外，品种（系）间有显著的差异，穗发芽抗性较强的品种的α-淀粉酶活性、籽粒吸水后的电导率和呼吸强度及籽粒吸水初期的吸水速率均比穗发芽抗性较弱的品种低，降落值与此相反。浸湿籽粒的α-淀粉酶活性、降落值、籽粒吸水24小时的电导率和吸吸强度、籽粒吸水0-75分钟的吸水速率等可作为穗发芽抗性的选择指标。鉴定穗发芽抗性时，最好在模拟雨湿条件下，既直接测定穗发芽情况，同时也采用多种选择指标，对穗发芽抗性作出综合评价。

PHYSIOLOGICAL AND BIOCHEMICAL CHARACTERISTICS OF PRE-HARVEST SPROUTING IN WHEAT

Thirty one wheat cultivars and lines grown in 3-replicate randomized block layout in 1984-1985 crop season were evaluated for germinability in the ear at 25, 35 days af. ter anthesis, falling number at 20 days after harvest ripeness.Alpha-amylase activity and endogenous ABA content of 15 cultivars were measured at harvest ripeness day and at 20 days after harvest ripeness, respectively. Te(?) cultivars were included in a field experiment in 1985-1986 crop season. Germinability in the ear during grain development, alphaamylase activity at 25, 35, 45 days after anthesis, electric conductivity and respiratory rate of grain immersed for 6, 12, 24 hours, falling number and water uptake rate of grain at 45 days after anthesis were determined.There were significant varietal differences in sprouting resistance. The percentage of germinated grain was positively and significantly correlated with alphya-amylase activity, electric conductivity, and respiratory rate of grain immersed and water uptake of grain at 45 days after flowering, while it gave an insignificant negative correlation with endogeneous ABA content. These results suggested that the alpha-amylase activity, falling number, electric conductivity and respiratory rate of grain immersed for 24 hours, and water uptake in 0-75 minutes could be used as selection criteria for sprouting resistance.