Study On Physical Characteristics Of Walnut Male And Female Sex Differentiation

Walnut(Juglans regia L) was a native species in China, which was a important economic tree species. The reason of lower economic benefit were low yield and poor quality. One important reason was that male flower of excessive consumed large number of nutrients, which seriously impacted on the female flower differentiation and development. The study was less on the physiological differentiation of walnut flower buds. Physiological differentiation of flower buds was a transformation process from leaf bud physiological state to flower bud physiological state within the buds growing point, and is the key which decided to the changing nature of shoot. During flower buds physiological differentiation, as the protoplast growth point was highly sensitive on internal and external factors, it was easy to change the direction of metabolism. This paper found, the laws of various factors changes and the relationship between factors and the flower bud differentiation in the course of physiological differentiation by studied the impact factors of sex differentiation, including flower buds endogenous hormone, polyamines, sugar, starch, protein, and other elements, which provides a theoretical basis for the production of walnut buds on the control of sex differentiation. The results are as follows:1. During physiological differentiation stage of walnut male flower, soluble starch content showed a downward trend after rising and reached a peak, and soluble sugar content showed a declining trend and in the lowest peak, soluble starch content was higher and soluble sugar content is lower. During walnut female flower buds physiological differentiation stage, soluble sugar was decline after an upward, and in the lowest peak, and soluble starch content was increased after downward and in peak, soluble sugar content is higher and soluble starch content was lower.2. During walnut male flower bud physiological differentiation stage, soluble protein content was downward after increased and reached a peak. And during physiological differentiation of the female flower stage protein content was upward trend.3. There was no obvious change of SOD activity during walnut male flower physiological differentiation stage,but POD activity showed downward trend after increasing and reach a peak. During female flower physiological differentiation stage SOD activity in relatively stable and no big fluctuations. While big change ranges of POD activity showed curve as up-down and then reach a peak.4. During male flower physiological differentiation period, IAA, dihZR and GA content showed downward trend after rising, while the ABA showed upward trend after decline, and then reached the lostest peak. ZR content keeped a lower level and showed little change. During female flower physiological differentiation stage, IAA, GA and ZR content showed declining trend after increase, dihZR content showed large change and wholly decreased, ABA content showed a curve of "down-up-down".5. During walnut male flower physiological differentiation preiod , the ZR/GA, ZR/IAA, ABA/IAA, and ABA/GA showed a curve as up-down-up-down. ZR/ABA showed a curve as up-down and reach the highest value. In walnut female flower differentiation stage ZR/IAA, ZR/ABA had shown a continuous upward trend, ABA/IAA did not change significantly, ZR/GA ratio showed a curve as "up - down - up"and then reach its peak, ABA/GA ratio had a large change, wholly showed a curve of down-up-down and then reached the lowest valley.6. During walnut male flower physiological differentiation stage, put, spd and spm content showed a curve as up-down and reach a peak. During walnut female flower physiological differentiation period, put, spd, spm and put content showed a curve as up-down-up.7. The ratio of male flower formation had significant positive correlation with GA content, POD activity, had evidently negatively correlated with the soluble sugar. The ratio of female flower formation had significant positively correlated with soluble starch and sugar, had evidently negatively correlated with the protein.