Analysis of the factors relating to vanetal differences in yielding ability and yearly variations in grain yield of nee bred for cold climate regions

2001 ~ 2003年，对12个新品种（系）与日本东北地区广泛栽培的秋竹町（Akitakomachi）和Hitomebore的产量及产量组成进行了田间试验比较。阐明了与产量相关的干物质生产和分配，以及造成品种间产量年际变化的因素。结果表明：(1)2001年产量为765 ~ 908 g m^<-2>， 2002年为700 ~ 770 g m^<-2>， 2003年为230 ~ 660 g m^<-2>。2003年6月底至7月底期间的低温和太阳辐射导致小穗绝育，导致成熟粒率低，随后导致所有品种籽粒产量下降。高抗寒品种（花野麦、多尻石和Hitomebore）籽粒产量的年际变化往往小于低抗寒品种，这是因为高抗寒品种的绝育小穗率较低，而高抗寒品种在2003年的产量较高。除2003年外，5年平均产量为赤竹町的735 g m^<-2> ~ Okiniiri的817 g m^<-2>，产量差异约为80 g m^<-2>(11%)。秋竹町和花野台产量低的原因是尽管PRG高，但碳汇规模小。另一方面，福hibiki、Okiniiri、Menkoina和Iwanan 7的高产主要是由于大的库大小和高PRG.3)在早熟阶段，所有品种的穗重增幅都远大于总干重增幅。茎叶鞘质量下降幅度较大的品种的PRG往往高于茎叶鞘质量下降幅度较小的品种。4)长茎品种的倒伏指数高于短茎品种。由于某些新品种的横截面指数和弯曲应力较大，其折断力矩大于大面积栽培品种。

Field experiments were carried out in 2001〜2003 to compare the yield and yield components of 12 new cultivars or lines with those of Akitakomachi and Hitomebore, the two widely-cultivated cultivars in the Tohoku region of Japan. Dry matter production and partitioning related to yield, and factors causing the yearly variation in yield among cultivars were also elucidated. The obtained results are shown as follows1)The grain yield ranged from 765 to 908 g m^<-2> in 2001, from 700 to 770 g m^<-2> in 2002 and from 230 to 660 g m^<-2> us 2003. Low temperature and solar radiation during the end of Jane to the end of July in 2003 caused spikelet sterilization, resulting in the low percentage of ripened grains(PRG), and subsequently reduced grain yield in all cultivars. Yearly variation in grain yield was often smaller in the high cool resistant cultivars(Hananomai, Hatajirushi and Hitomebore) than in the low cool resistant ones because of a lower percentage of sterilized spikelets and the higher yield in the former cultivars in 2003.2)The average yield in 5 years, except in 2003, ranged from 735 g m^<-2> in Akitakomachi to 817 g m^<-2> in Okiniiri, and the yield difference was about 80 g m^<-2>(11%). The low yield in Akitakomachi and Hananomai was because of a small sink size despite a high PRG. On the other hand, the high yield in Fukuhibiki, Okiniiri, Menkoina and Iwanan 7 was mainly caused by a large sink size and a high PRG.3)In the early ripening stage, the increase of panicle weight was much greater than that of total dry weight in all cultivars. Cultivars with a larger decrease in stem and leaf sheath weight often had a higher PRG than those with a smaller decrease in stem and leaf sheath weight.4)Lodging index was larger in the long-culm cultivars than in the short-culm ones. The breaking moment of a culm was larger in some new cultivars than in the widely cultivated ones because of a larger cross section index and bending stress in the former.