不同生长型桃的叶脉结构与树体结构的差异与关系

摘要

为探讨开张型、直立型、垂枝型、帚形、矮化型和紧凑型不同生长型桃树叶脉结构与树体结构的关系,为桃矮化密植栽培、早期选择提供理论依据.以6种不同生长型桃为试材,对其树体结构特征和叶片形态、叶脉结构进行研究,并对树体结构与叶脉结构的关系进行分析.结果表明: 6种生长型桃的叶片角度大小为62.76°~73.50°,没有显著差异,而分枝角度存在显著差异.其中对一级枝基角而言,垂枝型93.92°最大,矮化型36.75°最小,其他4种生长型居中;而一级枝腰角和梢角的变化规律在6种生长型中表现出相似规律,即垂枝型最大,开张型居中,其他4种次之且相互之间差异不显著.在叶片结构特征方面,直立型的叶片长度11.01 cm为最小,但叶柄长2.41 cm最大,紧凑型叶片长度16.20 cm、叶宽4.57 cm、叶面积47.28 cm2均最大,6种生长型的叶脉均为真曲行羽状脉;直立型二级脉数量最多,垂枝型二级脉数量最少;开张型二级脉角度最大,矮化型二级脉角度最小.6种生长型桃叶脉结构和树体结构相关性分析结果表明:开张型、矮化型、紧凑型中,二级脉数量与一级枝梢角之间存在负相关关系,且仅在开张型中两者相关性达到显著水平,相关系数为-0.970,而在直立型、垂枝型和帚型中,二级脉数量与一级枝梢角之间有正相关关系;在开张型、矮化型、紧凑型中二级脉角度与一级枝梢角呈正相关,且紧凑型中两者相关性达到显著水平,相关系数为0.953,其余生长型中两者之间有负相关关系.桃叶脉的二级脉角度和二级脉数量的差异在一定程度上可以反映不同生长型桃树体结构的变化,可作为早期选择桃不同生长型的一项直观形态标记.%The relationship between the open type,upright type,weeping type,broom type,dwarf type and compact type peach leaf vein structure and the different growth habits of peach tree architecture were explored to provide a theoretical basis for the breeding of peach dwarfing and high density by using different growth habits of peach resources and early selection.The characteristics of tree structure,leaf shape and leaf vein structure were observed by using six growth habits of peach as materials.Moreover,the relationship between the six growth habits of peach tree structure and vein structure were analyzed.The results showed:The average angle of the leaves in six grow types of peach ranged from 62.76° to 73.50° and showed no obvious difference among each other.However,the branch angle exhibited significant difference among six growth types of peach.For the basal angle of 1st order branches,weeping type was maximum(93.92°) while dwarf type was minimum (36.75°),the other four growth type were medium.However,the lumbar angle and top angle of 1st order branches showed the similar change rules in the six growth types of peach which displayed the maximum level in weeping type and the medium level in open type,and exhibited no significant difference among four other growth types.The characteristics of leaf structure in six growth types of peach were also investigated.The leaf length of upright type which was minimum (11.01 cm),while its petiole length was maximum(2.41 cm).The leaf length and leaf width of compact type peach was 16.2 cm and 4.57 cm respectively,and possessed the maximum average leaf area (47.28 cm2).All the leaf veins of six growth habits of peach was eucamptodromous venation pinnate.The number of secondary veins of upright type was highest while the weeping type had the least secondary veins.The open type had the maximum angle while the dwarf type had the minimum angle.Correlation analysis of leaf vein structures and tree structures in six growth habits of peach was performed.The results indicated that there was a negative correlation between the numbers of secondary vein and the top angle of 1st order branches in open type,dwarf type and compact type,especially in open type which correlation coefficient reached a significant level (-0.970).In another hand,there was a positive correlation between the numbers of secondary vein and the top angle of 1st order branches in the uprigh type,weeping type and broom type.In the open type,dwarf type and compact type,the angle of secondary vein had a negative correlation with the top angle of 1st order branches and only in the compact type their correlation coefficient reached a significant level (0.953).There was a negative correlation between angle of secondary vein and the top angle of 1st order branches among the other three growth types.The differences of leaf secondary veins angle and the numbers of secondary veins of peach veins could reflect the changes of different growth types of peach tree structure in a certain extent.It could be a morphological marker for early selection of different growth types of peach.