摘要
[ Objective] The aim of this study was to provide a theoretical basis for breeding selection, matching parents and the identification of traits during early period. [ Method ] With Shanli （ Pyrus ussuriensis Maxim） , S2 × Shanli （vigorous）, S2 x ShanU （dwarfing）, S2, super-dwarfing germplasm as the matedais, the dwarfing traits of each germplasm were identified by indices including leaf stomata density, branch-cortex ratio, leaf thickness, palisade tissue thickness, paisade-spongy ratio and vessel density. [Result] Among five kinds of pear germplasms, Shanli with strong growth potential had the smallest branch-cortex ratio, leaf thickness, palisade tissue thickness and palisade-spengy ratio, but the largest stomata density and vessel density. On the contrary, super-dwarfing germplasm with weak growth potential had the largest branch-cortex ratio, leaf thickness, palisade tissue thickness and palisade-spongy ratio, but the smallest stomata density and vessel density. There was a difference in stomata density, branch-cortex ratio, leaf thickness, palisade tissue thickness, palisade-spongy ratio and vessel density for every germplasm. [ Conclusion] Stomata density, branch-cortex ratio, leaf thickness, palisade tissue thickness, palisade-spongy ratio and vessel density can be used as indices of identification for pear growth potential in early period.
[目的]为梨育种选择、选配亲本及性状的早期鉴定提供理论依据。[方法]以S2×山梨(乔化)、S2×山梨(矮化)、S2、山梨、极矮化种质为材料,从叶片气孔密度、枝皮率、叶片厚度、栅栏组织厚度、栅海比、导管密度等指标来判断各种质的矮化性状。气孔密度的测定:选择实生苗主干中部、向阳面成熟叶片,10:00～10:30采叶。观察气孔时用指甲油涂抹叶背主脉中间两侧,干燥几分钟后,用镊子将指甲油层揭下,放在载玻片上,盖上盖玻片,利用Olympus显微图像分析仪分析,选择气孔密度中等的视野,观察气孔密度和大小。枝皮率的测定:选取一年生枝条10个,利用游标卡尺按十字交叉法分别测量除皮前后的枝条直径,以(1-ab/AB)×100%计算枝皮率(A、B为枝纵横径,a、b为去皮后枝纵横径),取平均值。叶片厚度、栅栏组织厚度、栅海比及导管密度的研究:采用石蜡切片法测定。材料用FAA液固定,利用切片机切片,在DMB5、Moticam 1300显微影像系统摄影,Motic Image Advanced 3.2捕捉图像并进行显微测量。[结果]5种梨种质中生长势强的山梨枝皮率(27.4%)、叶片厚度(200.5μm)、栅栏组织厚度(93.8μm)及栅海比(0.75)最小,而气孔密度(396.00个/mm^2)和导管密度(377.7个/μm^2)最大。生长势弱的梨极矮化种质枝皮率(45.0%)、叶片厚度(248.3μm)、栅栏组织厚度(140.4μm)、栅海比(1.59)最大,而气孔密度(235.75个/mm^2)和导管密度(287.0个/μm)最小。各种质在气孔密度、枝皮率、叶片厚度、栅栏组织厚度、栅海比、导管密度之间存在显著差异(P<0.05)。[结论]气孔密度、枝皮率、叶片厚度、栅栏组织厚度、栅海比以及导管密度可作为梨树体生长势早期鉴定的指标。
基金
Supported by National Natural Science Foundation(30560091
30960231)~~
