芸薹素内酯对稻草基质育秧水稻秧苗生理特性及栽后生长的影响

【目的】筛选出机插水稻基质育秧芸薹素内酯(BR)适宜的施用方法及最佳用量。【方法】以中早39为供试材料,采用稻草基质旱育秧方式,探究BR不同处理方式和浓度对机插早稻秧苗生理特性及栽后生长的影响。【结果】施用BR可以提高秧苗的抗氧化保护酶活性,降低丙二醛含量,增加可溶性蛋白含量、总糖含量及C/N,秧苗根系活力提高了13.24%~48.31%,利于形成抗性强的健壮秧苗;喷施方式对提高秧苗超氧化物歧化酶、过氧化物酶、过氧化氢酶活性效果最佳,基施方式对降低秧苗丙二醛含量效果最好。施用适量BR也可促进秧苗机插后长出新叶、新根及返青,喷施方式效果最好;浸种、喷施方式还能增强秧苗机插后20~30 d的单株分蘖力。【结论】播种前和出苗后进行两次适量的BR处理,有利形成壮苗和栽后活棵返青及分蘖,以播前0.15 mg/L浸种和秧苗1叶1心期0.10 mg/L喷施效果为好。

Effects of Brassinolide on Physiological Characteristics and Growth of Straw Substrate-cultured Rice Seedlings After Transplanting

【Objective】Our goal is to find the suitable application method and optimum dosage of brassinolide (BR) for straw substrate-cultured rice seedlings.【Method】The effects of three application patterns of BR (seed soaking, spraying, basal application at different concentrations) on physiological characteristics and growth in mechanized-transplanted early rice seedlings were estimated, with straw substrate-cultured Zhongzao 39 seedlings as test material.【Result】BR application could enhance antioxidant protective enzyme activities of seedlings, reduce MDA contents, increase soluble protein content, total sugar contents and C/N, increase root activity of seedlings by 13.24%-48.31%, which were conducive to the formation of robust seedlings with strong resistance. Spraying method had the best effect on increasing SOD, POD and CAT activities of seedlings, while basal application of BR had the best effect on reducing MDA content of seedlings. The right amount of brassinolide could also promote the growth of new leaves; new root and recovery after transplanting, spraying method had the best effect. The tillering ability per plant was enhanced by seeds soaking and spraying at 20-30 d after mechanized-transplanting.【Conclusion】BR application before sowing and after seedling emergence had favorable effects on cultivation of strong rice seedlings, turning green and tillering after transplanting, The concentration of 0.15 mg/L of brassinolide for seed soaking before sowing and 0.10 mg/L for spraying at 1.5 leaf age were better.