玉米花药培养及再生植株倍性鉴定

对影响玉米花药培养的几个因素及再生植株的倍性鉴定的结果表明、基因型是影响玉米花培效果的重要因素,杂交种的花培效果好于不稳定系,不稳定系又好于自交系.N_6与正_(14)两种培养基都适于花药培养,但正_(14)培养基优于N_6培养基.特别是液体培养基效果更好.花药接种的适宜时期为单核中期和后期.单核后期又稍好于单核中期,单核早期的花药不能诱导愈伤组织.单倍体与二倍体花粉植株之间叶片气孔保卫细胞长度差异极显著,长度小于29μm的为单倍体.大于29μm的为二倍体或多倍体.鉴定的准确性可达到95%.因此可利用测量气孔保卫细胞长度的方法鉴定花粉植株的倍性.     

Efficient plant regeneration via organogenesis in “Egusi” melon (Colocynthis citrullus L.)

Plant regeneration protocol of “Egusi” melon (Colocynthis citrullus L.) was established using three local (“Ejagham”, “Sewere” and “Barablackedge”) and one improved (NHC1-130) cultivars. Cotyledonary explants of different lengths (1/2, 1/4 and 1/6) excised from 4- or 8-day-old seedlings germinated in vitro were cultured on MS medium supplemented with different concentrations of 6-benzylaminopurine (BA). The best results were obtained when cotyledons from 4-day-old seedlings were cut into 2 (1/2) halves. Plant regeneration was optimal on medium containing 5 mg/l BA, yielding 86.3%, 77.0% and 76.3% shoot induction frequencies amongst the three local cultivars of “Ejagham”, “Sewere” and “Barablackedge”, respectively. In NHC1-130, the highest shoot induction frequency (85%) was obtained on medium containing 2 mg/l BA. Adventitious shoots were elongated on medium containing 0.1 mg/l BA and successfully rooted on hormone-free MS medium. Flow cytometric analysis revealed 70% of the plants to be diploid.     

大麦小孢子再生植株气孔保卫细胞长度与倍性的相关性

为了建立一种快速鉴定大麦小孢子来源植株倍性的方法,对大麦品种"花30"不同倍性(种子来源二倍体,小孢子来源单倍体和单倍体加倍系)早期植株的不同叶位、不同叶片部位的气孔保卫细胞长度进行了测定,考察了不同取材部位气孔保卫细胞长度的差异,对种子来源二倍体、小孢子来源单倍体和单倍体加倍材料的气孔保卫细胞长度的分布进行了区分。结果表明,"花30"单倍体材料的气孔保卫细胞长度在不同叶位以及不同叶片部位差异较小,而单倍体加倍材料和种子来源二倍体材料受叶片部位影响较大,单倍体和二倍体材料间气孔保卫细胞的长度差异显著,而单倍体加倍材料和种子来源二倍体材料间气孔保卫细胞长度未观察到明显差异。单倍体和单倍体加倍材料气孔保卫细胞的长度值范围分别为26.9~37.7μm和36.7~62.1μm;利用37μm临界值可对大麦小孢子来源的DH群体中的单倍体进行快速区分。     

蔬菜作物多倍体育种研究进展

对蔬菜作物多倍体育种研究的主要进展进行了综述。重点对蔬菜多倍体的 获得途径、多倍体的植物学特征、同源三倍体的不育性、四倍体的低稔性、抗逆性研究进行了综述，介绍了多倍体在蔬菜育种上的应用，并提出了蔬菜多倍体育种尚待解决 的关键问题。     

不同倍性西瓜的叶表皮微形态特征比较

扫描电镜观察结果表明,随着西瓜倍性的增加,叶片保卫细胞和表皮细胞增大,叶片单位面积上的气孔和表皮细胞的数目减少,细胞的大小与西瓜倍性呈正相关,单位面积上的细胞数目与西瓜倍性呈负相关。通过FDA荧光记数法观察,4x、3x和2x的叶片保卫细胞中的叶绿体数目分别为19.9±3.4,15.9±2.2,11.5±1.5,其比例约为4∶3∶2,与西瓜的倍性一致。根据此方法可以快速有效地对西瓜倍性进行早期鉴定。     

Determination of Ploidy Level and Nuclear DNA Content in Tunisian Populations of Atriplex halimus L.

Atriplex halimus L. (Chenopodiaceae) (Saltbush) is a perennial species used as a fodder shrub for livestock in arid and semi-arid areas, particularly in North Africa. The aim of this work was to determine whether differences in ploidy level and/or nuclear DNA content exist among populations from widely-separated sites in Tunisia. We determined nuclear DNA content and chromosome numbers for populations of A. halimus from seven different locations (Gabes, Medenine, Tataouine, Monastir, Tunis, Sidi Bouzid, Kairouan). The chromosome counts showed that all the Tunisian populations, plus a population from Eraclea (Italy), were tetraploid (2n = 4x = 36) whereas a population from Cala Tarida (Spain) was diploid (2n = 2x = 18). With respect to nuclear DNA, the 2C DNA content of population Cala Tarida was estimated to be 2.41 pg. There was no significant difference among the tetraploid populations (or among plants within populations), whose 2C DNA content ranged from 4.92 to 4.97 pg.     

甲基胺草磷诱导大蒜多倍体的研究

以通过生理休眠的紫皮大蒜Z-006-10鳞茎茎尖为试材,利用固体培养基中添加甲基胺草磷的离体诱导方法,研究甲基胺草磷不同处理浓度和时间对紫皮大蒜体细胞染色体的诱导效果,并利用形态观察、根尖细胞染色体计数及流式细胞仪分析等方法对得到的再生植株进行倍性鉴定。试验结果表明：10 μmol?L-1甲基胺草磷处理6 d,四倍体诱导率最高,达32.87%。形态观察结果表明,得到的四倍体植株多倍体形态特征明显,与二倍体植株差异明显。根尖染色体压片观察表明,四倍体染色体数为2n=4x=32,对照为2n=2x=16。流式细胞仪倍性分析表明,四倍体体细胞DNA的相对含量是二倍体的2倍,其结果与染色体计数法鉴定结果一致。     

萝卜游离小孢子培养及胚再生植株研究

[目的]探讨在自然生长条件下若干因素对萝卜（RaphanussativusL．）小孢子胚诱导及胚再生植株的影响。[方法]首先探讨不同萝卜品种的出胚能力,然后分析热激、低温预处理和培养基对小孢子培养的影响,最后研究胚状体再生成苗与植株继代培养情况。[结果]对22份萝卜材料进行游离小孢子培养,12份获得胚状体,3份获得再生植株,出胚材料中90％以上为杂种一代。4℃低温预处理0～3d小孢子出胚率无明显差异;培养基中加入1～2滴0．5％活性炭和一定浓度6-BA可显著促进小孢子诱导产生胚;不同萝卜品种适宜的热激温度和时间有所不同;发育正常的子叶型胚成苗率为100％;胚萌发分化早期适宜培养基为B5＋2％蔗糖＋1．2％琼脂,后期可逐渐将琼脂浓度降低;FCM测定小孢子植株自然加倍率为30％,单倍体占少数,四倍体与嵌合体（二、四倍）均为30％;秋水仙素处理单倍体植株,人工加倍率达60％。[结论]该研究完善了萝卜游离小孢子培养技术,可提高单倍体获得频率,加快这一技术在育种实践中的应用步伐。     

Ploidy level studies on the <Emphasis Type="Italic">Dioscorea cayenensis</Emphasis>/<Emphasis Type="Italic">Dioscorea rotundata</Emphasis> complex core set

The Guinea yams, Dioscorea cayenensis Lam. and D. rotundata Poir. (D. cayenensis–D. rotundata complex), represent a highly important crop, widely distributed in the humid and semi-humid tropics. The ploidy levels of 170 accessions of the core set of Guinea yams from West African countries was determined using flow cytometry with propidium iodide staining. One hundred and eight of the genotypes were found to be tetraploid, 47 were hexaploid and five were octoploid. One mixoploid individual containing tetraploid and hexaploid nuclei was also detected. A deeper analysis considering each separate taxon revealed that while for D. rotundata the majority of individuals were tetraploid, for D. cayenensis this ploidy level was not detected in any of the accessions. Also, no association between ploidy level and place of cultivation was found for the evaluated germplasm. The obtained data is highly valuable for breeding programs of Guinea yam, especially for the optimization of future hybridization experiments directed to the genetic improvement of this economically important crop.     

不同倍性西瓜果实不同糖含量比较

试验采用8组高代自交二倍体品种西瓜,相应人工诱导的同源四倍体及二倍体和四倍体杂交的同源三倍体为材料,分析不同倍性西瓜总糖、果糖、葡萄糖和蔗糖含量的差异。结果表明,不同倍性西瓜果实成熟时期总糖、果糖、葡萄糖和蔗糖含量存在差异,总糖和果糖含量有同样趋势,为四倍体〉三倍体〉二倍体;葡萄糖含量为四倍体〉二倍体〉三倍体;蔗糖含量为三倍体〉四倍体〉二倍体。