Effect of temperature on flower morphogenesis and pollen viability of garlic
In order to explore the effect of temperature on the mechanism of garlic sterility,two garlic cultivars,Chengxianhanzhong garlic and Dutch garlic NL-3,were used as experimental materials in this study.Differences of chromo-some variation and pollen viability in the processes of flower bud differentiation and pollen mother cell meiosis of two garlic cultivars under room temperature(average temperature of 23℃)and low temperature(average temperature of 17℃)were compared by squash technique and Alexander staining method.The results showed that the flower bud differentiation process of the two garlic varieties under low temperature treatment was 9-10 days longer than that under room temperature treatment.At different temperatures,there were significant differences in the proportion of abnormal chromosome behavior and mature pollen viability during the meiosis of pollen mother cells in the two varieties.At low temperature,the proportion of normal chromosome behavior and the activity of mature pollen during meiosis of NL-3 pollen mother cells increased from 5.47%and 4.01%at room temperature to 29.65%and 26.17%respectively,with significant differences.However,low temperature treat-ment could not significantly increase the proportion of normal chromosome behavior and the activity of mature pollen during meiosis of pollen mother cells in Chengxian-hanzhong garlic.In conclusion,the response of male game-tophytes of different garlic varieties to temperature is signifi-cantly different.The male gametophyte of Dutch garlic NL-3 is more sensitive to temperature and is a potential variety for fertility maintenance and recovery.