Biomasses in Different Organs of Rice Cultivars Developed During Recent Forty-Seven Years in Jilin Province, China

To understand the changes in yield, harvest index （HI） and biomass of aboveground parts of rice, 33 japonica rice cultivars released from 1958 to 2005 were planted. During the 47 years, the grain yield increased from 9 118.36 to 15 060.1 kg/hm2 and HI from 0.46 to 0.55. In the genetic improvement, the total number of tillers per plant decreased, and the biomass per unit area slightly increased at the harvest stage. The increases of yield and HI resulted from the increased biomasses of effective tillers and single stem, and the increase of biomass per stem was related to the increased biomasses of different organs along with the genetic improvement. The stem and sheath biomass at heading and the leaf biomass at 30 days after heading showed the highest increase, up by 75.17% and 49.94%, respectively. The biomasses of leaf and stem-sheath at 10 days after heading, and biomass per stem at 30 days after heading were obviously correlated with the yield. The results indicate that the genetic improvement has resulted in the increase of yield and HI. This increase is correlated with the decrease of total tiller number per plant, and increase of biomasses of effective tillers and single stem. The leaf biomass after heading and the stem and sheath biomass at 10 days after heading can be used as selection criteria for breeding high yielding rice cultivars.

复合肥运筹对旱作水稻抗倒伏能力的影响

在大田旱作条件下以绥粳18水稻品种为试验材料,使用吉农大抗倒专用肥,并设置T1,10:0:0、T2,7:2:1、T3,5:3:2、T4,3:4:3共4种基肥、分蘖肥和穗肥比例,探究适宜的复合肥运筹模式对旱作水稻倒伏特性的影响。结果表明:与一次性底肥施入(T1)相比,其他处理降低了株高、重心高度,增加壁厚,在成熟期T3处理较T1处理第1、2、3节间抗倒伏指数提高了65.29%、77.17%、63.16%。T3处理相比于T1、T2、T4处理产量分别增加了43.30%、8.16%和9.71%,氮素吸收利用率分别提高了178.72%、43.43%和52.33%。T3处理有助于增强旱作水稻茎秆抗倒伏能力和氮素吸收利用率,最终达到高产抗倒的目的。