高温下喷施水杨酸和磷酸二氢钾对中稻生理特征和产量的影响

为探寻减轻水稻抽穗开花期高温热害的技术途径,以3个籼型杂交稻品种为材料,于2017—2018年在江西省吉安县、余干县、南昌县进行田间试验.在抽穗开花期自然高温下,设置叶面喷施5个不同浓度的水杨酸(SA)处理(SA₁～SA₅分别为100、500、1000、1500、2000 μmol·L^-1)和5个不同浓度的磷酸二氢钾(KH₂PO₄)处理(K₁～K₅分别为7.35、14.70、22.05、29.40、36.75 mmol·L^-1),并以叶面喷施蒸馏水为对照(CK),分析中稻生理特征和产量.结果表明: 与对照相比,SA处理和KH₂PO₄处理分别降低了剑叶丙二醛含量,提高了叶绿素、可溶性糖、可溶性蛋白、脯氨酸含量和超氧化物歧化酶、过氧化物酶活性,其中SA₂和K₃处理效果最好.SA₂、SA₃和K₃、K₄处理提高了水稻穗粒数、结实率和产量,其中SA₂和K₃处理效果显著,与对照相比,SA₂处理分别使穗粒数、结实率和产量增加了7.0%、4.0%和11.9%,K₃处理增加了3.9%、4.7%和6.6%.抽穗开花期高温下,采取叶面喷施500 μmol·L^-1 SA或22.05 mmol·L^-1 KH₂PO₄的技术措施可显著提高中稻产量.

Effects of spraying salicylic acid and potassium dihydrogen phosphate on physiological cha-racteristics and grain yield of single-season rice under high temperature condition

To explore new practical means of alleviating the negative effect of heat stress on rice plants during the heading-flowering stage, a field experiment was conducted in Ji’an, Yugan, and Nanchang counties of Jiangxi Province from 2017 to 2018 with three indica hybrid rice varieties. Under ambient high temperature condition during the heading-flowering period, we sprayed five concentrations of salicylic acid (SA) (SA₁-SA₅: 100, 500, 1000, 1500, 2000 μmol·L^-1) and five concentrations of KH₂PO₄ (K₁-K₅: 7.35, 14.70, 22.05, 29.40, 36.75 mmol·L^-1) on the leave of rice, with deionized water as the control (CK), to mesure the physiological characteristics and grain yield. The results showed that compared to CK,plants treated with SA and KH₂PO₄ had higher chlorophyll content, soluble sugar content, soluble protein content, proline content, supero-xide dismutase activity, and peroxidase activity, but a lower malonaldehyde content, among which SA₂ and K₃ treatments performed the best. The treatments of SA₂, SA₃, K₃, and K₄ increased the number of grains per panicle, seed-setting rate, and grain yield, with the effects of SA₂ and K₃ treatments being significant. Compared to CK, the SA₂ treatments enhanced the number of grains per panicle, seed-setting rate, and grain yield by 7.0%, 4.0%, and 11.9%, respectively; the K₃ treatments enhanced the number of grains per panicle, seed-setting rate, and grain yield by 3.9%, 4.7%, and 6.6%, respectively. The optimal measure was spraying 500 μmol·L^-1 SA or 22.05 mmol·L^-1 KH₂PO₄, which could significantly increase grain yield of single-season rice under high temperature condition during the heading-flowering period.