Dynamics of extractable carbohydrates in Pisum sativum. II. Carbohydrate content and photosynthesis of pea cuttings in relation to irradiance and stock plant temperature and genotype

Abstract
Rooting ability was studied for cuttings derived from stock plants of wild type pea seedlings and seedings of two mutants deficient in photosystem II activity and chlorophyll. Stock plants were grown at 15, 20, 25 or 30°C at 38 W m‐2. Cuttings were rooted at 20°C and at an irradiance of 16 or 38 W m‐2. The rooting ability seemed to be correlated with the initial carbohydrate content only at 38 W m‐2. Based on the findings of the present study it may be concluded that for pea seedlings the growth temperature is more important than photosynthesis as regards accumulation of extractable carbohydrates. During the rooting period carbohydrates are necessary for root formation, but the effect of the iradiance on the number of roots formed is not mediated by the carbohydrate content. Under specific rooting conditions it is possible to correlate the initial carbohydrate content with the rooting capacity of the cuttings within a phenotype, but not always when different phenotypes are considered. The results indicate a connection between the metabolic activity of the cuttings and their ability to form adventitious roots.