PHOTOSYNTHESIS IN DIFFERENT MULBERRY CULTIVARS

The leaf architecture, net photosynthetic rate, (CO2)-C-14 fixation pa ttern and chlorophyll content were studied in mulberry cultivars. Ligh t microscopic studies exhibited various characteristics of leaf archit ecture such as the stomatal number, cuticle thickness, length of palis ade cells, and interveinal distance among the local mulberry cultivars Kanva-2, Mysore local and S41. Kanva-2 was superior among the studied cultivars because it had the highest photosynthetic (CO2)-C-14 fixati on rate. The short-term products of carbon fixation studied by radiotr acer techniques, autoradiography and chromatography showed that the am ino acids and sugar phosphates were predominantly synthesised in compa rison with organic acids and sugars in all three cultivars. Kanva-2 al so showed the highest incorporation of (CO2)-C-14 in amino acid fracti on (41 %) as compared to Mysore local (34 %) and S41 (28 %). The domin ant synthesised amino acids included glycine, serine and alanine. One hour (CO2)-C-14 fixation products were also different among the cultiv ars: Kanva-2 showed maximum incorporation in sucrose. Hence Kanva-2 ha d efficient mechanism of carbon fixation and utilization for synthesis of sucrose.