Study On Physiological Mechanism Of Male Sterile Of Chestnut (Castanea Mollissima Blume)

Chestnut is a king of monoecious and diclinous plant, and its male flowerquantity is specially big, the ratio of female and male flowers is 1:2400～4400. Thesemale flowers used a great deal of nutritions, and this limited the enhancement ofchestnut yield seriously. But male sterility may reduce the consumption of treenutrition and enhance the yield and so on. So male sterility has the importantapplication value in the production of fruit tree and the breeding. But there had notbeen reported about mechanism of chestnut male sterility in domestic. In order tostudy the mechanism of chestnut mail sterile, 5-year-old male sterile variety of'Fulaiwuhua' and male fertile variety of 'Dahongpao' were uesd in this study, and thechanges of morphology characters and morphodifferentiation, some protectiveenzymes activities and MDA content, and endogene hormone contents during maleinflorescence abortion were studied. The rusults were so follows:1. The length of male inflorescence of male sterile variety of 'Fulaiwuhua' wasshorter than that of 'Dahongpao', and changed yellow when it was 2.5～4 cm,afterwards wilting and fell Off, but male fertile variety of 'Dahongpao' continuedgrowing and could elongate above 16cm.2. The male inflorescence morpho differentiations were studied by paraffin method.The results showed that the differentiation process can be divided into 6 stages,including formation of the primordium of the male inflorescence, the floral cluster,the dividual floret, the floral envelope, the stamen, and the anther. The floral clusterprimordium period of male sterile variety 'Fulaiwuhua' was 3d late than that of malefertile variety 'Dahongpao',and its vascular bundles were maldevelopment; theindividual floret primordium period of 'Fulai Wuhua' was 3d later than that of'Dahongpao' and its vascular bundles were still maldevelopment; in the period offloral envelope primordium,the vascular bundle cell arrangement of 'Fulaiwuhua' wasloosed, and the vascular bundle cell arrangement of 'Dahongpao' was tightness andclear; the stamen primordium period of 'Fulaiwuhua' was 4d late than that of'Dahongpao'; stamen of 'Fulaiwuhua'began to degenerate in anther period, stoppeddevelopping and couldn't form pollen grain.3. The activities of SOD, POD, CAT and the content of MDA of male sterile variety of 'Fulaiwuhua' and male fertile variety of 'Dahongpao' were determined during thedevelopment of male inflorescence. The results showed that, the SOD activities ofmail sterile variety were higher than that of male fertile variety and the changetendency was basic consistent and the earlier period was higher than the later periodduring the development of male inflorescence and when the male inflorescence wouldfall off in May 24th the SOD activity was 93.1% times of SOD activity of May 1th;the POD activities of mail sterile variety were higher than that of male fertile varietyat the early stage of male inflorescence development, and rose obviously when themale inflorescence was dropping, and it was 1.4 times of 'Dahongpao'; the CATactivities of male sterile variety were obviously higher than that of male fertile varietyand their changes trend was the same; the MDA contents of mail sterile variety wereobviously lower than that of male fertile variety except the male inflorescence wasdropping. It was suggested that the destroying of active oxygen eliminating systemmight be the physiological reason of male inflorescence abortion.4. The content of IAA, GA₃, ZT and ABA of male sterile variety of 'Fulaiwuhua' and male fertilevariety of 'Dahongpao' were determined during the development of male inflorescence. Theresults showed that, the IAA content of mail sterile variety were lower than that of male fertilevariety except the male inflorescence was sprouting during the development of male inflorescenceand when the male inflorescence would fall off the IAA content of 'Fulaiwuhua' was only 8% of'Dahongpao'; the GA₃ content of mail sterile variety were higher than that of male fertile variety,and there exited significant difference in the early period, but there exied less difference in thelater period; the ZT content of male sterile variety were obviously higher than that of male fertilevariety; the ABA content of male sterile variety were higher than that of male fertile variety, andthere exited significant difference in the later period, when the male inflorescence would fall offthe ABA content of 'Fulaiwuhua' was 44.1 times of 'Dahongpao'. In endogene hormoneequilibrium aspect, the ratios of IAA/ABA and GA₃/ABA of 'Dahongpao' were significant or verysignificant higher than that of 'Fulaiwuhua', and the ratios of GA₃/IAA and ZT/ABA of'Fulaiwuhua' were significant or very significant higher than that of 'Dahongpao' exceptindividual time, and the change tendency wasn't consistent.