油菜秸秆还田对水稻根系分布及稻谷产量的影响

根系健康是水稻正常生长及高产的前提,为明确油菜秸秆还田方式和还田量对水稻生长及产量的影响,以秸秆不还田作为对照,设置秸秆半量还田(1.5 t/hm2)、全量还田(3.0 t/hm2)、超量还田(4.5 t/hm2)3个还田量以及秸秆覆盖还田(FG)、秸秆翻埋还田(FM)两种还田方式,通过盆栽和大田试验相结合,研究秸秆处...     

Response of the grain yield and quality of hybrid rice to weak light stress北大核心CSCD

In this study, three rice varieties, Byou268 (low light-sensitive type), Nei5you768 (intermediate type), and Yixiangyou1108 (low light-tolerant), were used as experimental materials to investigate the yield and quality responses of different rice varieties to low light stress under normal light (CK) and low light (SH). The results showed the following: (1) Compared with normal light, the decrease in Yixiangyou1108’s 1 000-grain weight, grain number per spike, and seed setting rate under low light treatment were much lower than those of Nei5you768 and Byou268. The yield decline of Yixiangyou1108 (46.5%) was significantly lower than that of Nei5you768 (56.5%) and Byou268 (69.8%). Yixiangyou1108 showed strong tolerance to low light stress in terms of 1 000-grain weight, seed setting rate, grain number per panicle, and yield. (2) Compared with normal light, the reduction in grain length and width of Yixiangyou1108 under low-light treatment was significantly greater than that of Byou268; however, the reduction in the length-width ratio did not reach a significant level. The amylose content and gel consistency of the rice were significantly reduced. The reduction in amylose content of Yixiangyou1108 (24.5%) was significantly lower than that of Nei5you768 (28.1%) and Byou268 (30.6%); however, the decrease in gel consistency of Yixiangyou1108 (14.7%) was significantly higher than that of Nei5you768 (9.8%) and Byou268 (8.1%). After low light treatment, the characteristic values of the RVA curve of rice changed. The peak viscosity and breakdown viscosity of Yixiangyou1108, Nei5you768, and Byou268 were significantly decreased, but the cold glue viscosity and setback viscosity were significantly increased, while there was no significant difference in the peak time and peak temperature. The response of 1 000-grain weight, grain number per spike, and seed setting rate under low light stress can be used as a yield index of rice breeding with low light tolerance; rice grain type, amylose, and gel consistency; and peak viscosity and hot paset viscosity in RVA characteristic values can be used as quality indexes of low-light-tolerant rice material breeding. © 2022 Science Press. All rights reserved.     

栽培密度对不同穗型水稻群体小气候及产量构成的影响

通过裂区试验(品种为主因素)分析R498(弯曲穗)及R499(直立穗)在0.23 m(行距)×0.12 m(穴距)、0.27 m×0.14 m、0.33 m×0.17 m、0.38 m×0.20 m、0.40 m×0.21 m栽培密度条件(副因素)下齐穗期和齐穗后20 d群体小气候及群体特征的响应情况.结果表明,在各栽培密度条件下,R499齐穗期群体最高温度平均值均较R498高1.52℃,齐穗后20 d,R499群体最高温度平均值较R498低0.66℃;齐穗期,R498、R499在稀植(0.38 m×0.20 m、0.40 m×0.21 m)时日平均光照强度较强,其中较最低光照分别高43.56%、16.22%,而齐穗后20 d,R498在密植(0.23 m×0.12 m、0.27 m×0.14 m)时日平均光照受抑制,R499在稀植时受抑制;R498、R499垂直光照在稀植时降低程度最大,在齐穗期分别降低97.96%、92.56%,齐穗后20 d分别降低94.81%、91.10%;随栽培密度的减小,R499株高、分蘖、穗弯曲度变化程度较R498更大;R498、R499在0.38 m×0.20 m处理下纹枯病发病率最严重,分别为66.67%、68.89%;两个材料产量均在0.27m×0.14 m处理下有最大值,且增产是通过有效穗数、穗重来实现的,而当密度过度减小时,R499产量性状将不再增长.综上,弯曲穗型水稻(R498)不适宜过度密植及稀植,直立穗型水稻(R499)可适当密植.