摘要：

低温逆境严重影响水稻尤其是机插稻的安全生产。为明确机插双季稻适宜植物生长调剂及其喷施时期,以早稻品种中嘉早17和晚稻品种H优518为材料,研究了不同植物生长调剂(烯效唑,C1;脱落酸,C2;壮谷饱,C3)与喷施时期(早稻:浸种,D1;一叶一心期,D2;两叶一心期,D3;移栽前,D4;返青期,D5;晚稻:孕穗期,F1;始穗期,F2;齐穗期,F3;齐穗后7 d,F4)对机插稻产量和抗寒特性的影响。结果表明,3种植物生长调剂中,壮谷饱处理茎蘖数最多,叶面积指数最高,干物质积累量最大,且显著高于其他2个处理。壮谷饱处理产量最高,早稻较烯效唑和脱落酸处理实际产量分别高7.58%,7.13%,晚稻壮谷饱较烯效唑和脱落酸处理实际产量分别高13.54%,11.59%。喷施时期方面,早稻于返青期喷施,晚稻于始穗期喷施,对产量形成各指标提升效果最佳,产量最高。分析产量构成因素,植物生长调剂及喷施时期主要通过提高水稻穗粒数而增产。不同植物生长调剂处理下抗氧化酶活性存在差异,早、晚稻SOD、POD及CAT活性均以壮谷饱处理最高,同时早稻返青期喷施,晚稻始穗期喷施植物生长调剂对提升抗氧化酶活性效果更佳。综合来看,湘南双季机插稻植物生长调剂选用壮谷饱,且早稻返青期喷施、晚稻始穗期喷施的抗寒增产效果最好。

关键词: 双季稻, 机插秧, 植物生长调剂, 产量形成

Abstract:

Low temperature stress seriously affects the safe production of rice,especially machine-transplanted rice.In order to clarify the suitable plant growth regulator and spraying periods for machine-transplanted double-cropping rice,the early rice variety Zhongjiazao 17 and the late rice variety H you 518 were used as materials.The effects of different plant growth regulators(Uniconazole,C1;Abscisic acid,C2;Zhuanggubao,C3)and spraying periods(early rice:soak seeds,D1;one leaf and one core stage,D2;two leaves and one core stage,D3;before transplanting,D4;during the greening stage,D5;late rice:booting stage,F1;initial heading stage,F2;full heading stage,F3;one week after full heading,F4)on the yield and cold-resistant characteristics of machine-transplanted rice were studied.The results showed that among the three plant growth regulators,the Zhuanggubao treatment had the largest number of stems and tillers,the highest leaf area index,and the largest dry matter accumulation,which were significantly higher than the other two treatments.The yield of Zhuanggubao was the highest.The actual yield of early rice was 7.58% and 7.13% higher than that of uniconazole and abscisic acid treatments respectively.The actual yield of late rice was 13.54% and 11.59% higher than that of uniconazole and abscisic acid treatments respectively.In terms of spraying period,early rice was sprayed at the greening stage,and late rice was sprayed at the initial panicling stage,which had the best effect on improving various indicators of yield and the highest yield.Analyzing the components of yield,plant growth regulators and spraying periods mainly increased yield by increasing the number of grains per panicle of rice.The SOD,POD and CAT activities of early and late rice were highest in the grain-stuffing treatment.At the same time,spraying plant growth regulators during the greening stage of early rice and spraying plant growth regulators at the beginning of earing stage of late rice were more effective in increasing antioxidant enzyme activity.Taken together,the plant growth regulator for double-cropping machine-transplanted rice in Southern Hunan is Zhuanggubao,and spraying during the greening stage of early rice and spraying at the beginning of earing stage of late rice have the best cold-resistant and yield-increasing effects.

Key words: Double-cropping rice, Machine transplanting, Plant growth regulator, Yield formation