Primary Study On Phyliological And Biochemical Basis Of Plant Dwarfing Of Ricinus Communis L.

By using the method of comparative physiology, the relationship between plant heights of four varieties of Ricinus communis L. and carbon metabolism, nitrogen metabolism, phytohormones, isoenzymes was studied. The main purpose is to elucidate the physiological mechanism of dwarfing of Ricinus communis L. on the above aspects, and to provide theoretical basis for the reasonable cultivation and selection of low-stem Ricinus varieties. The results indicated(:1)The fast increasing stage of plant height was from early July to early August.(2)The accumulation of more soluble sugar in leaves in the former developing stage, and higher invertase activity and lower content of reducing sugar in the middle and later developing stages, were advantageous to the increase of plant height. In the ears, soluble sugar, reducing sugar and sucrose contents in low-stem varieties were higher than in high-stem varieties, while the invertase activity was lower in low-stem varieties.(3)The soluble protein content and glutamine synthetase activity were positively correlated to plant height, and free amino acid content in leaves in the middle and later developing stages of Ricinus communis was negatively correlated to plant height on significant level. In the ears, soluble protein, total nitrogen and free amino acid contents in low-stem varieties were higher than in high-stem varieties, while the glutamine synthetase activity was lower in low-stem varieties than in high-stem varieties. (4)In different stages, isoenzyme profile of the same variety was different, which reflected developmental specificity. And in the same stage, different isoenzymes were also different, for example, in the middle developing stage, low-stem varieties (Zhebi-3 and CNS-268) had seven bands of POD isoenzymes and high-stem varieties (9800 and 1900) had three. And on June 13th, Zhebi-3 and CNS-268 varieties had four bands of SOD isoenzymes and 9800 and 1900 varieties had four, too, but their Rf values were not the same. In earlier developing stage enzyme activity and strength of low-stem varieties were higher than those of high-stem varieties.(5)GA and IAA contents in low-stem varieties were lower than in high-stem varieties, while ABA and ZR contents in the two low-stem varieties were higher than in the two high-stem varieties(.6)In fast-growth period, plant height was negatively correlated to oil ratio and yield, To conclude, carbon and nitrogen metabolism, isoenzymes, phytohormone contents are all related to plant height.