马铃薯丰产群体植株光合产物日变化规律的研究(四) 淀粉含量及其日变化

全生育期中,马铃薯丰产群体和一般群体植株叶片和茎秆的淀粉含量日变化趋势相同,呈昼高夜低的抛物线形的变化。两群体植株块茎淀粉含量的日变化,在生育前期和后期变化趋势一致,均表现为夜高昼低,而块茎增长期,由于丰产群体块茎夜间增长非常迅速,而出现夜间低峰现象。整个生育期间两群体块茎淀粉含量高于叶片和茎秆,并均随生育期的推移而逐渐增加,但丰产群体始终低于一般群体。前期叶片淀粉含量高于茎秆,后期茎秆和叶片含量相近。茎秆既是马铃薯的支撑和运输器官,也是光合作用的重要辅助器官。

STUDIES ON THE PATTERNS OF PHOTOSYNTHATE DIURNAL VARIATION IN POTATO HIGH YIELD POPULATION PLANTS Ⅳ. STARCH CONTENT AND ITS DIURNAL VARIATION

During the whole growth period, the diurnal variation of starch content in leaves of both high and common yield population plants shows the parabolic change, that is high in daytime and low at night, but the range of diurnal variation for the high yield population is larger than that for the common yield population. The diurnal variation of starch content in stems of both populations is similar to that in leaves, but the range of variation is small. The starch content in stems of high yield population is lower than that in stems of common yield population because of the vigorous growth of former population stems. As for the starch content in tubers, the diurnal variation for both populations shows the same trend in both tuber initiation stage and starch accumulation stage, that is high at night and low in daytime. But in tuber swelling stage the diurnal variation of the starch content in tubers of high yield population shows a low peak at night because of the rapid growth of tubers at night. During the whole growth period, the starch content in tubers of both populations is higher than that in leaves and stems. The starch content in each organ of high yield population is lower than that of common yield population.