抽穗开花期喷施MeJA对粳稻产量和品质的影响

茉莉酸甲酯（MeJA）可有效促进水稻颖花开放,使父母本花时相遇,提高制种产量,但MeJA对水稻产量和米质的影响研究报道较少。以辽宁稻区具有代表性的4个粳稻品种为试验材料,研究了抽穗开花期喷施不同浓度的MeJA对产量和米质性状的影响。结果表明,喷施MeJA可显著降低粳稻产量,且浓度越大,降低的程度越明显。MeJA对产量结构中的有效穗数、穗粒数和千粒重没有显著影响,但对结实率影响显著,尤其一次枝梗和二次枝梗的结实率均随MeJA浓度的升高呈极显著下降趋势,而结实率的显著下降是产量下降的主要原因。喷施MeJA可显著降低粳稻品质。与对照相比,不同浓度MeJA处理下精米率显著下降,且浓度越大,降低程度越明显,整精米率在高浓度处理下降低程度达极显著水平。但垩白粒率和垩白度变化不显著。随MeJA喷施浓度升高,稻米蛋白质含量提高,而直链淀粉含量和食味值下降。本研究可为生产上充分发挥MeJA调控花时的作用,同时避免对产量和米质的不利影响提供理论依据。

Effects of Spraying Methyl Jasmonate on Yield and Grain Quality of Japonica Rice during Heading and Flowering Stage

Methyl jasmonate (MeJA) can promote the opening process of rice florets, enable the floret opening time of parents to meet each other and increase yield of hybrid seed production effectively. However, few researches on the affects of MeJA on rice yield and grain quality. In this study, four representative japonica rice cultivars from Liaoning rice region were used as test materials. Different concentrations of MeJA were used during the heading and flowering stages. Yield and grain quality traits were measured during harvesting period. The results indicated that spraying MeJA could significantly reduced the yield of japonica rice. The greater the concentration was, the more obviously the degree of reduction caused. MeJA had no significant effect on the number of effective panicles, grains per panicle and 1000-grain weight of yield components, but had significant impact on seed-setting rate. In particular, the seed-setting rates of primary branch and secondary branch were significantly decreased with the increase of MeJA concentration. It could be inferred that after spraying MeJA, the significant decrease in seed-setting rate was the main reason for the decline in the yield of japonica rice. Spraying MeJA could significantly decreased the quality of japonica rice. Compared with the control, under different concentrations of MeJA treatment, the milled rice rate was decreased significantly, and the greater the concentration was, the more obviously the decrease caused. The head milled rice rate was decreased significantly under treatment of high concentration MeJA. The effects of spraying MeJA on chalky grain rate and chalkiness degree did not reach up to a significant level. The protein content increased and amylose content and taste score decreased with the increase of MeJA concentration. This study can provide a theoretical basis on full utilization of MeJA in regulating floret opening time in production and avoiding adverse effect on yield and grain quality.