Studies On Bud Grafting Measure And Screening Of Different Scion Rootstock Combination And Graft Union Physiological Foundation Of Castanea Mollissima

The Chestnut(Fagaceae)genus Castanea Miller,is one of the most common economic tree species in China.This study took 1a and 3a of ’3113’ and 3a’Dabanhong’ seedlings as rootstocks,and the full bud of’ ’Yanshanzaofeng’ and ’Yanlong’ variety perennial chestnut tree as scion.The seedlings of chestnut were budded in 4 periods and 2 methods.Through out the observation of 18 d survival rate and shooting rate,in addition to the determination of basic physiological and biochemical indexes of bud rootstock.The combination of rootstocks and the method of bud grafting of chestnut bud in Qianxi area were selected,with the exploration of the physiological basis of rootstock which affects the survival of chestnut budding.The results were as follows:(1)For chestnut budding in Qianxi area,the survival rate of bud grafting of 3a rootstocks were higher than 1a rootstocks,and 3a’Dabanhong’ rootstocks was better than 3a’3113’ rootstocks.Different scion varieties contribute less influences on bud survival.The different effects of budding methods contribute to bud survival is also related to the weather,’T’ budding shooting rate is higher in rainy weather,square budding rate is higher in sunny weather.Late June was suitable period for 1a rootstocks budding,mid-August was suitable period for 3a rootstocks budding.(2)1a rootstocks budding survival was significantly affected by climatic factors and 3 a rootstocks budding survival was greatly affected by nutrient content changes.Hot and rainy weather had adverse effects on budding survival.The moisture content,nitrogen content,phosphorus content and soluble sugar content of phloem of rootstock were correlated with bud survival.The content of nitrogen,phosphorus and soluble sugar had significant influence on 3 a rootstocks budding surviaval,and water content had significant influence on 1a rootstocks budding survival.(3)New shoots on the 3a rootstocks is stronger than those on the 1a rootstocks.There was no significant difference between the new shoots of different budding methods,and the new shoots were more robust with earlier budding period.The correlation between the overwintering rate and the length and base diameter of the shoot was significantly positive.During the wintering period,the weak new shoots were susceptible to freezing injury and inactivation,results to germinate failure in the coming year.Therefore,during the overwintering period,certain package protection measures is necessarily taken,non-woven anti-cold cloth was a better choice as wrapped materials.