Comparative Analysis on Rice Plant Type of Two Super Hybrids and Shanyou63

<正> The characteristics of plant type and physiological indices for photosynthesis were analyzed using two super hybrid rices, Liangyoupeijiu and LiangyouE32 as materials, and an indica hybrid, Shan-you63 as a control. Based on the present analysis and various theories and breeding practices on rice plant type, a model of plant ideotype for super hybrid rice (indica) in the lower reaches of Yangtze River Valley was proposed. This was: a length of 35 - 40 cm for top leaf with a width of 2 cm, and that of 50 - 55 cm and 55-60 cm, respectively, for the second and third leaves from top, meanwhile, having a leaf angle of 5°, 10°and 15° respectively, and a curvature of 1 - 1. 5 cm-1for the leaf face at heading stage; the uppermost three leaves keeping their activities for as long as 70 d, which could lead a LAI of 3 at full ripeness; loose plant type with thin (SLW=2.5-3 g cm-2, dry weight) and curve-slant leaves during early growing stage, and compact plant type by thick (SLW=4 - 5 g cm-2) and erect leaves du