不同程度干旱对温州蜜柑树势和成花生理的影响

Effects of different degrees of drought stress on plants and flowering physiology in Satsuma mandarin(Citrus unshiu‘Yura’)

为探明温州蜜柑对干旱处理的响应以及经干旱处理后“成花素”基因FLOWERING LOCUST(FT)和分生组织基因APETALA1(AP1)在茎和叶片中的表达谱,以两年生盆栽温州蜜柑‘由良’为实验材料,进行轻度干旱、中度干旱、重度干旱处理,处理时间分别为20、30、40 d,追踪植株树势生理、成花生理以及成花相关基因FT和AP1相对表达量。结果表明:中度干旱胁迫30 d处理对温州蜜柑树势影响不大,花芽生理分化和形态学分化较其他处理组早,且FT和AP1基因的相对表达量最高。即中度干旱胁迫30 d不仅不会对树势造成严重损伤,而且是促进植株开花的较为适宜的干旱胁迫强度和时长,成花早的效应在基因表达水平上也得到了进一步验证。

In order to study the responses of Satsuma mandarin‘Yura’plants to different drought treatments and the relative expression levels of flowering related gene FLOWERING LOCUS T(FT)and meristem related gene APETALA1(AP1),two-year-old Satsuma mandarin plants were treated with various degrees of limited water,including well watering(CK),light drought(LD),moderate drought(MD)and severe drought(SD),whose soil moisture were 15%-20%,12%-15%,8%-10%,and 4%-6%,respectively,and kept for 20,30,and 40 d,respectively.After treatments,the plant physiology,flowering physiology and relative expression levels of flowering related genes FT and AP1 were tracked.The results indicated that the treatment of MD for 30 d affected the plant growth slightly and the physiological and morphological differentiations of flower buds were earlier than those of other treatment groups.The relative expression level of FT reached peak under the treatment of MD for 30 d,and the relative expression levels of AP1 in stems and leaves were higher at 30 d after MD treatment.In general,moderate drought for 30 d is the suitable inducement condition of flower bud’s morphological differentiation in Satsuma mandarin,and will not cause serious damage to trees.Also the effect of early flowering has also been further verified at the gene transcription level.