植物生长调节剂对香蕉植株的矮化效应

【目的】筛选降低香蕉株高而不影响产量的植物生长调节剂，探究其使用次数对香蕉植株的矮化效应。检测适宜浓度烯效唑对香蕉叶片中几种防御性抗氧化酶活性、可溶性蛋白含量以及钾、钙、镁、磷含量的变化，进一步解析除矮化作用外，烯效唑对香蕉植株生长的正向辅助作用，为在香蕉生产上安全、合理使用植物生长调节剂提供参考。【方法】采用根部淋施法评价烯效唑（XX）、多效唑（DX）、矮壮素（AZ）、甲哌（JP）、复配剂0802和0501等植物生长调节剂对香蕉植株的矮化效应。施用0.3 g/株烯效唑15、20、25 d后，测定香蕉叶片中多酚氧化酶（PPO）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、苯丙氨酸解氨酶（PAL）及可溶性蛋白、钾、钙、镁和磷含量的变化。【结果】根据矮化效果评价标准判断，香蕉植株矮化后可在节间距3～5级别内正常生长。1次矮化处理中，XX1、XX3、DX1、AZ1、JP2、JP4、0501、0802处理香蕉株高降幅在11.67～24.00 cm;2次矮化处理中，JP2、DX1、JP4、0802、AZ1、0501、XX3处理香蕉株高降幅在29.67～39.00 cm，均可正常生长。香蕉株高...

Dwarfing Effects of Plant Growth Regulators on Banana Plants

【Objective】The study was conducted to screen plant growth regulators that could shorten the plant height of banana without affecting the yield, and explore the dwarfing effects of their application times on banana plants. Furthermore, appropriate concentrations of uniconazole were detected for identifying the changes in the activities of several defensive antioxidant enzymes, and the contents of soluble protein, potassium, calcium, magnesium and phosphorus in banana leaves, to further analyze the positive auxiliary effect of uniconazole on banana plant growth in addition to dwarfing effect, which would provide references for the safe and rational use of plant growth regulators in banana production.【Method】The dwarfing effects of several plant growth regulators including uniconazole (XX), paclobutrazol (DX), chlormequat chloride (AZ), mepiquat (JP), compound agents 0802 and 0501 on banana plants were evaluated by root spraying method. The contents of polyphenol oxidase (PPO), superoxide dismutase (SOD), catalase (CAT), phenylalanine ammonia lyase (PAL), soluble protein, potassium, calcium, magnesium and phosphorus in banana leaves were determined after 15, 20 and 25 days of 0.3 g/plant XX treatment.【Result】According to the evaluation standard of dwarfing effect, banana plant could grow normally in the 3-5 level of internode distance after dwarfing. Under one dwarfing treatment, the banana plant heights of XX1, DX1, 0501, XX3, JP2, 0802, AZ1 and JP4 treatments were decreased by 11.67-24.00 cm. The banana plant heights of JP2, DX1, JP4, 0802, AZ1, 0501 and XX3 under two dwarfing treatments were decreased by 29.67-39.00 cm with normal growth. It found that the banana plant height was shortened with the increase of the concentrations and application times of these grow regulators. XX3, 0802 and 0501 treatments could promote the early bud shooting of banana, and the duration periods were 8-19 days earlier than that of the control; The plant shooting was neat. The shooting rate of XX3 under two drarfing and 0802 treatment was 62.01% and 89.32%. The yield per plant showed decreasing trends with the increase of XX concentration. The plant yields of banana were 27.26, 25.62 and 23.45 kg for the one time treatment of XX1, XX3 and XX5, respectively. Of which, the yields per plant of XX3 and XX5 treatment were significantly decreased compared with that of the control (27.45 kg). The yields per plant of banana treated with 0802 and 0501 were 27.37 and 26.99 kg, respectively, and there was no significant difference with that of the control. It was found that the yield performance of banana plants was similar under the two dwarfing treatments of different plant grow regulators. Under the treatment with low concentrations of chlormequat chloride and paclobutrazol, the early shooting of banana could be promoted. Whereas the shooting of banana was delayed when the treating concentration was above 0.2 g per plant, and the plant yield was greatly affected or even reduced. The uniconazole treatment could increase the activities of PPO, CAT and PAL in banana leaves as well as the contents of soluble protein, calcium, magnesium, phosphorus and potassium, and enhance plant resistance.【Conclusion】It is recommended to use uniconazole, compound agents 0802 and 0501 as banana dwarfing agents with concentration ranging of 0.2-0.3 g/plant in banana production, and the newly planted banana could be dwarfed once. Banana is more susceptible to paclobutrazol (DX) and chlormequat chloride (AZ), which are not recommended.