马铃薯源器官建成规律研究

马铃薯源的状况与源器官叶面积的大小 (LAI)、功能叶片的工作时间 (LAD)和工作效率 (NAR)密切相关。不同密度和施肥处理下 ,马铃薯群体LAI、LAD在全生育期内均呈单峰曲线变化 ,NAR呈阔U形曲线变化。但在因素中量组合下 ,LAI有良好的发展动态 :前期迅速升高 ,稳定期长 (18d左右 ) ,最大值达 6 10 4以上 ,生育后期下降缓慢 ,LAI与出苗后天数的拟合方程为Y =- 2 392 +0 2 35 6X - 0 0 179X2 ;LAD与出苗后天数的拟合方程为Y =- 0 4 2 5 2 9+3 9345X -0 1186 6X2 ,总光合势达 2 5 86 2× 10 4m2 ·d 6 6 7m2 ;NAR在苗期可达 2 0 95 g m2 ·d ,后期可回升到13 93g m2 ·d。在本试验设计的栽培措施中 ,密度、施磷量、种肥氮量及追氮量对马铃薯源的影响较大。

THE DYNAMIC OF SOURCE STRUCTURE IN POTATO

The status of source in potato is closely related to leaf area index (LAI), leaf area duration (LAD) and net assimilation rate (NAR).Under different plant density and fertilizer regime, LAI and LAD changed as a curve with a single peak, whereas NAR changed as a wide “V” during the whole growing season. Under optimum cultivation conditions, LAI was in better status, increasing quickly from the emergence to full blooming, keeping high level for a long period of time (about 18 days) with a maximum of 6 104, and then decreasing slowly at late growing stage. The equation estimated between LAI and days after emergence was Y=-2 392+0 2356x-0 0179x 2; whereas the equation between LAD and days after emergence was Y=-0 42529+3 9345x-0 11866x 2. The total LAD was 25 862× 104 m 2 d/667 m 2. The NAR was 20 95g/m 2 d at emergence, decreased later on, and then regained to 13 93 g/m 2 d. In this research, the factors of plant density, P and N fertilizers applied at planting, and top dressing of N fertilizer had apparent influence upon the source of potato.