早籼中83-49高产株型及生理特性的研究

PLANT TYPE AND PHYSIOLOGICAL CHARACTERS OF ZHONG 83-49,A HIGH-YIELDING CULTIVAR OF EARLY INDICA RICE

通过株型和生理特性研究,中83-49与广陆矮4号(简称广4)相比的特点是:苗期冠层叶开角大7～13.2°,株型较松散;穗期秆粗、叶挺、穗齐,中下叶层(高度为0～60cm)平均透光率17.3%,大5.14%.苗期耐寒、素质好,充实度6.91mg/cm,重0.61mg/cm;齐穗至成熟期 CGR,RGR 和 NAR,分别为24.49g/M^2·d,0.03g/g·d 和6.66g/M^2·d,高12.2%,6.9%和9.0%;籽粒容量25.88ml/千粒,大13.8%;叶、茎、鞘物质输出率21.54%,高3.07%;强弱势籽粒异步灌浆特点明显;讨论了该品种的高产栽培措施.

The plant type and physiological characters of Zhong 83-49,a new released rice(Oryza sativa L.Subsp.indica)cultivar with better yield performance,was compared withthat of Guangluai 4.(Guang 4),the control.The results indicated that the leaf angle at thecanopy of Zhong 83-49 slanted 7-13.2°more than the control,and its plant type seemedslightly open at the seedling stage.However,at the heading stage,the new cultivar charac-terized with thiker culms,erect leavcs and uniform panicles,its averages relative light inten-sity at the mid and lower layers of the canopy(0-60 cm above the ground)was 17.3%,5.14percentage point more than that of Guang 4.Besides the cold tolerance and good quality,the seedling weight per hight unit of Zhong 83-49,was 6.91mg/cm,0.61mg/cm heavier than the control.The crop growth rate(CGR),relative growth rate(RGR)and net assimila-tion rate(NAR)during the stage of full heading to muturity,were 24.49g/m^2.d,0.03g/g.d and 6.66g/m^2.d respectively,all were higher than the control.In comparisonof grain sink between these two cultivars,it was found that Zhong 83-49 was25.88ml/1000 grains,13.8% bigger than Guang 4;and the matter exported from leaves,culms and sheathes was 3.07 percentage point higher in the former than in the latter.How-ever,there was obvious differentiation in filling speed of dominant spikelets from weakones in Zhong 83-49.The practices for further improving the yield of this new cultivar was discussed.