Research On The Formation Mechanism Of Roughbark Fruit Of Korla Fragrant Pear Caused By Calcium Deficiency

The experiment was conducted in two fragrant pear orchards of Shayidong Horticultural farm of Bazhou.This article has mainly analyses the formation mechanism of Roughbark Fruit was studied by comparing the contents of mineral elements,calmodulin,endogenous hormones and activities of lignin synthesis related enzymes in different parts of the fruit during the growth and development period of Korla fragrant pear,and spraying calcium on with severe occurrence of Roughbark Fruit orchards in past years.The effects of calcium on mineral elements,calmodulin,endogenous hormones and enzyme activities in leaves and fruits were studied.The results show that:1.Expansion period to maturity,the content of Ca in the peel,pulp and fruit core of the persistent calyx and dropping calyx Roughbark Fruit was significantly lower than that of the persistent calyx and dropping calyx normal fruit,while the N,P and K contents were significantly higher than that of the persistent calyx and dropping calyx normal fruit;The content of Mg in the peel,pulp and fruit core of the persistent calyx and dropping calyx Roughbark Fruit was significantly lower than that of the persistent calyx and dropping calyx normal fruit at the mature period,and there was no significant difference at the expansion period.The contents of K and P in the adjacent leaves of Roughbark Fruit were significantly higher than adjacent leaves of the normal fruit,and the Ca content was significantly lower than adjacent leaves of the normal fruit.Whether it is Roughbark Fruit,normal fruit or Ca treated fruit,the order of Ca element accumulation is as follows:peel>fruit core>pulp,and the order of N element accumulation is as follows:fruit core>peel>pulp.The content of P element in the pulp of the inflated period was higher than that in the peel and the fruit core,and the content of P element in the fruit core of the mature period was higher than that in the peel and pulp.There were no regular changes of K and Mg in different parts of fruit.Expansion period to maturity,the contents of N,P,K,Ca and Mg in the leaves were significantly higher than those in the fruit.The formation of Roughbark Fruit may be related to the excessive content of N,P and K in the peel,pulp and fruit core of the Roughbark Fruit and the high content of P and K in the adjacent leaves of the fruit,thereby resulting in Ca deficiency,It was not related to the uneven distribution of Ca,N and P in leaves and different parts of the fruit.2.Expansion period to maturity,the contents of IAA and GA3 in the peel,pulp and fruit core of the persistent calyx and dropping calyx normal fruit were significantly higher than those of the persistent calyx and dropping calyx Roughbark Fruit.At the mature period,The content of IAA and GA3 in the adjacent leaves of Roughbark Fruit was significantly lower than that in the adjacent leaves of normal Fruit.At the inflated period,the ABA content in the peel,pulp,fruit core,adjacent leaves of the persistent calyx and dropping calyx Roughbark Fruit were significantly lower than that of the persistent calyx and dropping calyx normal fruit and adjacent leaves,at the mature period was significantly higher than that of the persistent calyx and dropping calyx normal fruit and adjacent leaves.Expansion period to maturity,the content of IAA and GA3 in the peel,pulp and fruit core of the calcium-treated persistent calyx and dropping calyx fruit was higher than that of the persistent calyx and dropping calyx Roughbark Fruit.The decrease of Ca concentration may affect the endogenous hormone content directly or indirectly through calmodulin,which may affect the activity of lignin synthesis related enzymes,leading to the formation of Roughbark Fruit.3.In the inflated period,the content of CaM in the peel,pulp,fruit core and adjacent leaves of the persistent calyx and dropping calyx Roughbark Fruit was significantly lower than that of the persistent calyx and dropping calyx normal fruit and adjacent leaves.In the mature period significantly higher than that of the persistent calyx and dropping calyx normal fruit and adjacent leaves;changes in Ca concentration affect the change in CaM content;therefore,it is believed that the CaM content in the mature fruit and adjacent leaves cannot be combined with enough Ca to form an active Ca2+-CaM complex,which can aggravate physiological metabolic disorders;calcium supplementation can increase Ca content in fruits and leaves,can effectively activate the calcium messenger system.4.The activities of lignin synthesis-related enzymes in pulp during fruit development were lower than those in peel and fruit core.Expansion period to maturity,the activity of lignin synthesis related enzymes in the peel,pulp and fruit core of the persistent calyx and dropping calyx Roughbark Fruit were higher than that of the persistent calyx and dropping calyx normal fruit.Calcium spray has a certain inhibitory effect on the enzyme activities related to lignin synthesis in the peel,pulp and fruit core.Although the CaM content of the Roughbark Fruit in the mature period was increase,due to Ca deficiency does not activate the calcium messenger system,it aggravates the metabolic disorder and causes the activity of lignin synthase,thereby forming lignin.Spraying exogenous Ca can effectively increase Ca content in fruit and leaf,effectively start calcium messenger system,and reduce the proportion of roughbark fruit.