分蘖角度动态型水稻的形态特征及生长特性分析

以前期分蘖半散生、抽穗后直立的分蘖角度动态型水稻材料DI508为研究对象，对照全生育期直立型材料9308和全生育期半散生型材料M09，研究了全生育期分蘖角度的变化和相关的生理生态特性。结果表明， DI508在分蘖期具有明显的丛生快长和拔节后直立抽穗的特性，生育后期上3叶功能稳定。其主茎的第1、第2和第3分蘖在始蘖期与水平地面夹角平均值分别为59.74°、62.94°和68.54°，与半散生水稻材料M09表现一致；抽穗后接近90°，与直立型水稻材料9308表现一致。DI508的分蘖成穗率为68.35%，较M09的66.24%增加309个百分点。DI508成熟期单株干物质量为155.54 g，较M09和9308分别高15.84%和64.09%；平均单蘖干物质量9.15 g，较M09和9308高63.69%和44.78%。拔节后至成熟，DI508的上3叶净光合速率平均值为26.89、25.69和24.83 μmol/（m2·s)，具有较强的光合功能。最后，讨论了分蘖角度动态型水稻前期半散生快长、后期直立灌浆特性的生长优势以及在水稻高光效、高产育种上的潜在利用价值。

Morphological and Ontogenic Characterization of Rice with Dynamic Tiller Angle

The tiller angle is very important for plant architecture and canopy structure in rice.Changes in tiller angle and relevant physiological and ecological characteristics were studied by using three varieties differed in tiller angle(9308,erect;M09,semi-scattered;and DI508,semi-scattered at the tillering stage and erect at the full heading stage)as materials.DI508 is characterized by fast growth at the tillering stage and erect culms after booting and its leaves maintain stable photosynthesis.At the initial tillering stage the tiller angles(between the horizontal and tiller)of the 1st,2nd and 3rd tillers on the main culm in DI508 were 59.74°,62.94° and 68.54°,respectively,similar to M09.After booting the angles changed into 90°,similar to erect rice 9308.The effective tiller rate of DI508 was 68.35%,3.09 percent point higher than that of M09.And the mean dry biomass per plant of DI508 was 155.54 g at the maturity stage,being 15.84% and 64.09% higher than those of M09 and 9308 respectively.Meanwhile,the mean dry biomass per tiller of DI508 was 9.15 g,being 63.69% and 44.78% higher than those of M09 and 9308,respectively.From booting to maturity the photosynthetic ability of the top three leaves of DI508 was stable and strong,with mean net photosynthetic rates of 26.89,25.69 and 24.83 μmol/(m2·s).Moreover,the potential roles of dynamic tiller angle character in rice breeding for high photosynthetic efficiency and high-yielding was discussed.