The purpose of this study is to recognize the phenotypic behavior of cytoplasmic male-sterile (cms) line of leaf mustard synthesized by intra-specific hybridization and identify genetically transmitted molecular markers related to cytoplasm. Phenotypic variations of both vegetative and floral organs were observed in cms and its maintainer line. Pistil fertility was reduced correspondingly and recovered progressively with backcrossing. In BC3, some flowers showed abnormality with pinnate, petaloidy, palm-like, carpelloidy or rudimentary silk-like stamens. The deformed floral phenotypes were also observed with closed or partially expanded corollas. By PCR-aided assay using specific primers from mitochondrial genes, atpA and one open reading frame (orf) were found to be distinctively present in the progenies of intra-specific F1 hybrid, BC2 and BC3, which were proved to be maternally transmitted and genetically stable in various backcrossed progenies. The cms specific orf corresponds to a 663 bp-sized fragment with its own initiator (ATG) and terminator (TGA). Furthermore, it was deduced to encode for 220 amino acids, named orf220 thereafter, and was shown to belong to the plant mitochondrial membrane YMF19-like protein family. Transcript of orf was exclusively present in cms and absent in its maintainer. Moreover, atpA gene was expressed in a larger transcript size in BC3 progeny than in the maintainer.

Sugar-accumulating patterns and compositions were compared between two oriental melon varieties, "Huangjingua" (Cucumis melo var. makuwa Makino) and "Yuegua" (Cucumis melo var. conomon Makino). Sucrose and reducing sugars were measured in different mesocarp tissues of developing fruits. They were all characterized by enhanced accumulation of glucose and fructose during early fruit development with almost no sucrose detectable. However, a transition of sucrose enhancement was accompanied by fruit maturing in the variety "Huangjingua", while no such transition was observed in the variety "Yuegua" that merely had a sucrose content throughout development. In "Huangjingua", both sucrose and total sugar gradients were observed, ascending from mesocarp adjacent to pedicle, middle part of mesocarp, and up to mesocarp adjacent to umbilicus. However, no obvious gradient in sucrose accumulation was seen among three mesocarp tissues examined. In terms of sweetness index, fructose is the chief contributor to sugar accumulation in both varieties. Also, the melon variety "Huangjingua" could be comparatively considered as a high-sucrose accumulator and "Yuegua" a minor-sucrose accumulator.

利用茎用芥菜细胞质雄性不育系原生质体培养获得了再生植株，并研究了影响原生质体培养的因素。结果表明，子叶是茎用芥菜原生质体培养最佳的外植体，10d苗龄的子叶原生质体在改良MS培养基上培养3d后发生第1次细胞分裂，6d后发生第2次分裂，3周后形成细胞团，5周后形成肉眼可见的小愈伤。培养基中缺少NAA或2，4-D都会降低愈伤组织的再生能力。在含一定浓度的NAA（0.25mg/L）和2，42D（0.25mg/L）培养基上诱导的愈伤组织质地致密且有光泽，芽的分化能力高；在MS+BA1mg/L+NAA0.2mg/L的培养基上芽的分化频率高达近29%，再生芽在1/2MS+NAA0.1mg/L培养基上生根，形成完整植株。

随着网纹甜瓜果实的发育，果实中葡萄糖和果糖的含量增加，蔗糖的快速积累发生在果实发育的中后期，高蔗糖积累型果实中蔗糖积累速率明显快于低蔗糖积累型。蔗糖磷酸合成酶活性在果实发育的前期短暂下降， 而后稳步上升，在果实发育的中后期高蔗糖积累型果实中该酶的活性显著高于低蔗糖积累型果实；随着果实发育，蔗糖合成酶的分解活性降低而合成活性升高。酸性和中性转化酶在未成熟果实中活性较高，而在成熟果实中很低；高蔗糖积累型果实中酸性转化酶活性显著低于同期低蔗糖积累型果实。合成蔗糖的酶活性小于分解蔗糖的酶活性时蔗糖几乎没有积累。根据这些结果推测，转化酶活性的下降、蔗糖磷酸合成酶活性的增加以及蔗糖合成酶分解活性的下降和合成活性的增加，是引起果实蔗糖积累的主要内在因子。

本文以“京欣1号”母本和“伊选”西瓜4天苗龄子叶为外植体，研究离体培养植株高频率再生体系。结果表明：“伊选”子叶远轴端外植体的再生频率仅为10%，子叶近轴端外植体在5mg/LBA+0.1mg/L IAA的激素组合下植株再生频率为100%，平均每个外植体的丛生芽数在所有组合中最多，为10-3个；“京欣1号”母本子叶近轴端外植体在2mg/L BA+0.5mg/L IAA激素组合下植再生频率为100%，平均每个外植体的丛生芽数在所有组合中最多，达6.9个。本试验条件下，子叶近轴端外植体接种4天即分化出不定芽，至再生苗的移栽仅需40天，在Ms+0.1mg/L NAA的生根培养基上的生根率为97.3%，移栽成活率达98.5%。