Research On Anatomic Structure Characteristic And Physiological Characteristic Of Cold-resistance In The Branch Of Introduced Armeniaca Vulgaris Var.ansu In Western Liaoning

This study took 12 families and 12 clones of Armeniaca vulgaris var.ansu as research objects,and used Armeniaca sibirica's families and clones which came from introduced region as contrast.We observed the anatomic structure of the lignified annual branches,and determined cold-resistance physiological indexes of families and clones under low temperature stress.Analysis of the relationship between the anatomic structure and physiological indexes.The aim was to explore the mechanisms of cold-resistance,also to select the anatomic structure indicators that reflect cold-resistance,We hope to provide theoretical guidance for the evaluation of introduction adaptability and breed high-quality seed in Western Liaoning.The main results were as follows:?1?The anatomic structure of the annual branch from inside to outside as follows:pith,xylem,cambium,phloem,cortex,epidermis.Compared with CK,the annual branch of Armeniaca vulgaris var.ansu had larger pith ratio,smaller xylem ratio,and the catheter density in xylem was higher.Among the families and clones,the ratio of xylem was highly significant negative correlation with pith ratio,the r are-0.936,-0.713 and highly significant positive correlation with the xylem-cortex ratio the r are 0.808,0.908.The ratio of cortex was highly significant negative correlation with the xylem-cortex ratio of the families and clones,the ratio of xylem in different clones the r are-0.945,-0.782.The ratio of xylem which affected the degree of lignification were the important anatomical structure indexes.According to the degree of lignification from high to low,the families were divided into A1,A2,A3,the clones were divided into JA1,JA2,JA3.There were highly significant different among families levels and clones levels.?2?Under low temperature stress,the electrical conductivity curves of the different families and clones showed increased tendency by‘S'type.The curves of soluble protein,MDA,POD,SOD showed‘ascending-descending'tendency.The curves of soluble sugar showed increased tendency.The electrical conductivity,soluble protein,POD and SOD increased sharply between-30³5?.The 170,210,J170,J171 were significantly superior to other families and clones.The families were superior to the clones.There was correlation among physiological indexes in different degrees.Among the families and clones,LT₅₀0 was in a highly significant positive correlation with MDA content,electrical conductivity and families'free-water/bound-water,the r are 0.918,0.911,0.872,0.911,0.722.LT₅₀0 was in a highly significant negative correlation with POD activity,soluble protein content,clones'SOD activity the r are-0.823,-0.832,-0.760,-0.735,-0.828.It could be as a single factor physiological indexes to evaluate the cold-resistance of Armeniaca vulgaris var.ansu.?3?The change rule of the physiological indexes in all levels was similar to families and clones under the low temperature stress.Except for soluble sugar content in families,the indexes'response degree for low temperature stress was A1,A2,A3 and JA1,JA2',JA3'according to strong-weak.Except for the POD activity,other indexes were significantly different and the results were consistent with all levels of anatomical structure index.The xylem ratio,cortex ratio,the xylem-cortex ratio,catheter density were significant correlation with LT₅₀.They were important anatomic indexes which could identify the cold-resistance.The results of regression analysis showed that the xylem ratio>44.56%,the cortex ratio<6.94%and the xylem-cortex ratio>6.79,catheter density<45.88 catheter/mm² which could be the identification standards for superior tree with cold-resistance.