Studies on the annuality and perenniality in the genus Oryza

本研究的目的是阐明米属一年生植物和多年生植物的生理特性。W492是O. glaberrima的一种菌株。22、对一个品种的玉米进行了比较，以确定(i)干物质在穗部的积累模式（ii）叶片的衰老和（iii）同化物在植株各部位的转运。我们认为W492是一年生的，因为即使在24小时的光周期下-12小时/12小时的温度为25/20‰的情况下，它也会在一年内死亡。22被认为是多年生植物，因为它可以在25/20的自然昼夜温度下持续生长一年以上。2个品系的穗部干物质积累模式基本一致，但W492比Norin no快一些。在成熟的初期。但这与前期试验的结果不一致，前期试验表明，W492的穗部干物质积累速度要比光光快得多。需要更多的实验来证实这一事实。叶绿素含量、叶绿素计读数SPAD值和氮素含量表明W492的叶片衰老速度快于Norin。22. 一年生和多年生植物的衰老差异非常明显。^<13>C分布在植株各部位的速率表明，同化物向穗部的转运一直持续到后期。22比1992年要多。由于W492的单株叶面积下降速度快于Norin。22、W492的单株同化能力下降幅度大于诺林。22. 因此，虽然诺林没有。在成熟阶段，22能够在残茬中保留一些同化物，而W492则不能。需要更详细的实验来推广年代性和多年性的结果。

The purpose of this study is to clarify the physiological characteristics of annuals and perennials in the genus Oryza. W492, a strain of O. glaberrima, and Norin no. 22, a cultivar of O. sativa were compared to ascertain (i) the accumulation pattern of dry matter into panicles (ii) leaf senescence and (iii) translocation of assimilates into plant parts. We consider W492 to be annual because it dies within one year even under a 24hr photoperiod-12hr/12hr temperature of 25/20ﾟC and we consider Norin no. 22 to be perennial because it continues growing mare than one year under natural day length-day/night temperature of 25/20ﾟC.The dry matter accumulation pattern in panicles was almost the same in both strains, though W492 was a little faster than Norin no. 22 at the early stage of ripenning. However, this was not in consonance with the results of the preliminary trial which showed that the accumulation of dry matter in panicles was much more faster in W492 than in Koshihikari (a cultivar of O. sativa). More experiments will be needed to confirm this fact.Leaf senescence indicated by chlorophyll content, SPAD values of a chlorophyll metre reading and nitrogen content was faster in W492 than in Norin no. 22. The difference in senescence between annual and perennial was very clear.The rate of ^<13>C distributed to the various plant parts showed that the translocation of assimilates to panicles continued till later stage in Norin no. 22 than in W492. As the leaf area per plant of W492 decreased more rapidly than Norin no. 22, assimilating capacity per plant of W492 declined more sharply than Norin no. 22. Therefore, while Norin no. 22 was able to reserve some assimilates in the stubble during ripenning stage, W492 was not able to do so.More detailed experiments are necessary to generalize the results on annuality and perenniality.