不同株穗型水稻超高产品种叶绿素含量变化规律及籽粒灌浆动态研究

Changes of Chlorophyll Content & Grain Filling Characteristics of the Super High-yielding Rice Cultivars with Different Plant and Panicle Types

对不同株、穗型水稻超高产品种叶绿素含量变化规律及籽粒灌浆动态的研究表明(1)株、穗型较好的半直立穗型品种上、中、下三部籽粒收获重量相差无几,分布均匀,灌浆速率高,灌浆物质充足,弱势粒得到了较好的充实;直立穗型品种,中部籽粒重量较小,弱势粒灌浆不足;大散穗型超高产品种为明显的异步灌浆,上、中、下部籽粒灌浆速率罪大值的时间相差较大,下部籽粒收获时籽粒重量不到上部的一半,灌浆动态最不合理。(2)半直立穗型品种倒三叶、倒二叶的叶绿素含量在抽穗至穗后20d内始终高于剑叶,其他类型品种的剑叶叶绿素含量在穗后10d高于其他叶片;同时半直立穗型品种不同叶龄剑叶叶绿素含量变化为理想的“升快降慢”型,直立穗型品种为“升快下降较慢”型;对照小穗多蘖形品种为“升慢降慢”类型,大散穗型品种为“升快降快”型。

To raise the population photosynthetic efficiency, Chen Wen-Fu （1987） thought, the quantity and the quality of photosynthetic organ should be increased. The photosynthetic capacity of panicle in rice is so weak that it＇ s contributive rate is less than 5 % to grain weight （Tsunoda S, 1965）, therefore, leaf is the main photosynthetic organ in rice. The chlorophyll content is an important index of leaf quality, and effect the economic yield and biological yield indirectly or directly. Many researchers focused on the relation between chlorophyll content and yield, but little research was on the law of variation of chlorophyll content. In rice super high yielding breeding, the law of variation of chlorophyll and resources with different chlorophyll contents have important theoretical and practical significance. The yield of rice is finally decided by the grain filling, which process was described by Kato（1993）, Zhu Qing-Sen（1988）, Gu Shi-Liang （2001）, et al. through linearity-plain model, but it is very simple and rough. Richards equation which was used in this paper can exactly describe the law of grain filling process. In 2001, 41 super high yielding rice cultivars with different plant and panicle types were arranged in a randomized block experimental design with three replications. Each experimental unit was composed of 5 rows 5 m long, 3 seedlings/ hole. Transplant density was 30 cm × 20 cm. Nitrogenous level was 150 kg/ha. In 2002, cultivar Ji-99F90, Ji-01-124, J-E262, Jite-623 and Chaochan-1 （CK） （Table 1 ） were used in the experiment, the design and cultivitive practices were the same as that in 2001. The results indicated that the chlorophyll contents of the 2nd and 3rd leaves from the top of cuhivars with semi-erect panicle was higher than that of flag leaf during 20 days after heading stage（ Fig. 3,4）, and only higher than that of flag leaf during 10 days after heading stage for other cultivars with different panicle types（Fig.7）. Cultivars with semi-erect panicle would be ideal for its chlorophyll content in flag leaves increased rapidly in early stage of development, and declining in later stage. The filled grain weight of the upper, the middle and the lower panicle was similar in that of semi-erect panicle type, which had higher grain-filling rate and a sufficient matter to fill the inferior grains （Table 3 and Fig.9,10）. The inferior grain weight of erect panicle type was largely lower than that of the superior one, the seed-filling stage was delayed （Table 3 and Fig. 9,10）. The large curved panicle type was so-called typical asynchronous type, the inferior grain weight was half of upper grains, and its grain filling characteristics was undesirable （Table 2 and Fig.9, 10）.