Abstract
Studies were carried out on the relationships between the photosynthetic rates and morphogenesis of leaves such as leaf thickness and stomatal distributions in the early growth stage of mulberry in spring. Apparent photosynthetic rates soon after unfolding showed negative value, but became positive in about one week thereafter, and reached the maximum in about 20 days after unfolding. Photosynthetic rates among varieties was in the order of Kenmochi>Kairyonezumigaeshi>Kairyoichinose≈Kokuso No. 21. Dark respiratory rate was maximal soon after unfolding and lowered thereafter. There existed high correlations between photosynthetic rates or dark respiratory rates and number of days after unfolding. Values of stomatal distribution and leaf thickness were small soon after unfolding but increased thereafter, and reached maximum in 20 days after unfolding. Between stomatal distribution or leaf thickness and number of days after unfolding, and furthermore, between stomatal distribution or leaf thickness and photosynthetic rates, high correlations were found. Thus, close relationships were recognized between increase of photosynthetic rates and leaf morphogenesis.
