| Castanea henryi(Castanea henryi Rehd.Et Wils.)is important woody grain in the south of China.C.henryi is monoecism plant with hermaphroditic flower bud and male flower bud,hermaphroditic flower bud extraction with a mixture of male and female flower inflorescence,male flower bud extraction with male inflorescence.At present,C.henryi proportion of male and female flowers serious imbalance in the production of medium and long term(the proportion of male and female flowers are generally reach to 1:2000?2500),the problem has not been effectively solved,leading to a lower production in a conventional cultivation.Therefore,the research on the rules of Castanea henryi bud differentiation,explore the technology of artificial control proportion of hermaphroditic flower bud has become a top priority.Using'Hua Li 4' as test materials,The research through field experiment,anatomical observation,physical and chemical analysis,proven C.henryi flower bud morphological differentiation process and characteristics,anther development characteristics,the analysis of enzyme activity in buds during flower bud differentiation,carbohydrate,soluble protein,minerals and other nutrients in the dynamic change rule,in order to provide theoretical basis for artificial regulation flower bud differentiation.The main results were as follows:1.The study of Castanea henryi flower bud morphological anatomy.The process of C henryi flower bud differentiation can be divided into the young shoots differentiation beginning period(June 1st to 20th),the male sequence primordium appear period(June 21th to July 20th),the young shoots differentiation stage before winter(July 21th to October 21th),the winter hibernation period(October 22th to December 30th),the young shoots differentiation period(January 20th to mid-may)five stages,and the young shoots differentiation period can be divided into three specific stage,the end of the winter after inflorescence primordium differentiation stage,flowers bract primordium differentiation stage and flowers primordium differentiation stage.By electron microscope inflorescence primordia apical growing point,found in the process of C.henryi bud differentiation,the nucleus became smaller marginalized,nuclear qualitative sparse,vacuoles increase gradually increase,the last small vacuoles into big vacuole,form a large central vacuole,organelles such as chloroplasts gradually increased at the same time.C henryi anther development can be divided into microspore mother cell,tetrad and microspore early,late microspore,the early 2-celled pollen and mature period,a total of six times,and the male external morphological differentiation characteristics and correlation with relatively stable internal cell development.The flower bud anatomical observation shows that the young shoots differentiation period before winter and young shoots period is impotant,it had a greater influence on the sex differentiation of flower bud differentiation end of Castanea henryi,is the key to reasonably control manually.2.Changes of the physiological characteristics of Castanea henryi bud.In Castanea henryi bud differentiation process,all kinds of nutrient content in the young shoots differentiation period before the winter late volatility changes obviously,and the young shoots differentiation of a-amylase activity,carbohydrate,soluble protein and mineral elements(N,P,K,Ca)had a great influence on the content of flower bud differentiation.In the whole process of flower bud differentiation,flower bud of SOD activity decline on the whole,hermaphroditic flower bud of SOD activity in August,November to April the following year,when the content is higher;male flower buds the highest content of SOD activity in June,1524.38 U/g·Fw,leaf bud in September content as high as 2117.67 U/g·Fw.Flower bud of a-amylase activity unimodal curve changes,hermaphroditic flower bud in August,the highest enzyme activity,a value of 61.728 mg/(g· min),male flower buds in March,the highest levels,is 44.092 mg/(g·min),lowest activity in November,as low as 2.204 mg/(g· min),and two kinds of flower bud between enzyme activity in different periods of time difference is more apparent.Starch content in the flower bud have almost the same change trend,is a"U" shaped changes:the young shoots differentiation and the end of the young shoots differentiation phase content is higher.Completely soluble sugar content in the hermaphroditic flower bud down-up-down-up change trend,the highest content in May,21.087 mg·g-1;male flower bud content in hermaphroditic flower bud shows bimodal curve changes,and in April the following year content is higher in August,17.068 mg ·g-1,19.373 mg· g-1.Hermaphroditic flower bud of reducing sugar,first increase then decrease after falling to rise again,male flower buds,first after rising downward trend.Flower bud of soluble protein in broadly similar change trend,the volatility change,peak values of completely mixed buds appear in the may,10.877 mg·g-1,male flower buds peak in September,8.944 mg·g-1.C/N in the hermaphroditic flower bud showed a trend of decline after rising first,male flower buds in the C/N shows bimodal curve changes,the first peak in September,the second peak in May.The tendency of the P and Ca content in flower buds broadly,are slowly rising,hermaphroditic flower bud of P in May is as high as 3.594 mg·L-1,Ca content peaked in April,36.238 mg·g-1.Flower bud is similar to the change trend of N content in the leaf bud,change is stable.K content in the flower bud is unimodal curve changes,hermaphroditic flower bud in May,the highest levels,5.664 mg·g-1;male flower buds in October,the highest levels.Zinc content show unimodal curve change.Leaf bud of Mn content is higher than that of flower bud;male flower bud Mg content is higher than hermaphroditic flower bud;hermaphroditic flower bud Fe content is higher than that of male flower bud.Therefore,the young shoots differentiation stage before winter and young shoots differentiation at the end is very impotant,but in the meantime can undertake artificial chemical regulation,in order to improve the flower bud in related nutrient content,eventually improve the proportion of female flowers. |
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