KARYO-RACES IN SPINACIA OLERACEA

Bose , Smritimoy , and Jules Janick . (Purdue U., Lafayette, Ind.) Karyo-races in Spinacia oleracea. Amer. Jour. Bot. 48(3): 238–241. Illus. 1961.—Cytological analysis of chromosome 1 of Spinacia oleracea, which contains the XY factor pair, revealed the existence of 3 distinct morphological types. The “standard” chromosome 1, the longest of the complement, is heterobrachial with one arm being about twice as long as the other. The most prevalent situation is for this “standard” chromosome pair to be homomorphic in staminate, monoecious, or pistillate plants. Some staminate and pistillate plants in the varieties ‘Spica’ and ‘Universal’ were found to be heteromorphic for the standard chromosome and a variant type, distinguished by a satellite on the short arm. In a cross derived from an accession PI 169671 from Turkey, which segregated for monoecious and pistillate types, half of the plants, irrespective of sex, were homomorphic for the standard chromosome and half were heteromorphic. The non-standard chromosome was longer and isobrachial, the added length apparently due to an additional segment on the short arm of the “standard” chromosome. Plants homomorphic for the satellited and isobrachial chromosome have been obtained.     

THE CHROMOSOMES OF SPLNACIA OLERACEA

Ellis , J. R., and Jules Janick . (Purdue U., Lafayette, Ind.) The chromosomes of Spinaeia oleracea. Amer. Jour. Bot. 47(3) : 210—214. Illus. 1960.—The somatic chromosomes of S. oleracea are described and each has been associated with one of the 6 morphological trisomics derived from triploid-diploid crosses. Of these 6 primary trisomies, reflex had been shown by genetic studies to be trisomic for the chromosomes carrying the sex-determining factors. This chromosome is the longest of the somatic complement and has a sub-median centromere. No obvious heteromorphism of this chromosome pair was observed in staminate plants. Heteromorphism involving this chromosome pair has been reported recently in 2 varieties of cultivated spinach by Zoschke (1956) and Dressier (1958) and was earlier reported by Araratjan (1939) for the wild species, S. tetandra. However, their accounts differ markedly from each other and with the present results in respect to the morphology of this chromosome pair. This study suggests the existence of races which differ with respect to the morphology of the chromosome pair containing the X Y factors.     

SEX DETERMINATION IN DIPLOID-TRIPLOID CROSSES OF SPINACIA OLERACEA

Mahoney , D. L. Jules Janick , and E. C. Stevenson . (Purdue U., Lafayette, Ind.) Sex determination in diploid-triploid crosses of Spinacia oleracea. Amer. Jour. Bot. 46(5): 372–375. 1959.—Segregation for sex in spinach was studied in a series of diploid pistillate × triploid staminate crosses. The genetic data indicated that the functional gametes from staminate triploids were not confined to n and n + 1 types. Cytological analyses of progenies from a number of 2n ♀ × 3n (XYY and XYY) ♂ crosses revealed similar but non-homogeneous types of chromosome segregation. These crosses produced 49.3% diploids, 17.9% trisomies, 0.5% with 14 chromosomes, 1.2% with 16 chromosomes, 11.4% with 17 chromosomes, 18.9% triploids, and 0.8% with 19 chromosomes. The reciprocal crosses produced a higher percentage of aneuploid types including 1.7% with 15 chromosomes. Segregation for sex in each of the various chromosome numbered progeny of diploid-triploid crosses was presented and analyzed.     

花椰菜与黑芥非对称体细胞杂种的鉴定分析

选用兼具抗黑腐病、黑胫病、根肿病的野生种质黑芥(B.nigra)作为供体,具有良好原生质体培养能力的花椰菜(Boleracea var.botrytis L.)基因型"0307"作为受体,供体叶肉原生质体经不同剂量UV照射处理后,通过PEG介导,与不经任何处理的受体下胚轴原生质体融合,培养获得再生植株.形态学观察显示再生植株的表型多样,呈偏向受体花椰菜类型及中间类型分布:SRAP分子标记特征表明,杂种中受体的遗传信息较为完整,而来自供体的特异扩增带丢失量约为20.0%-97.8%,且不同杂种中存在热点丢失序列;约23.0%的再生植株其染色体数目小于供、受体染色体数之和;采用流式细胞仪对再生株的细胞DNA含量进行分析,结果显示,20%的植株其DNA含量小于供、受体DNA含量总和.对22棵再生植株进行了黑腐病人工接种抗性鉴定,17棵再生植株表现良好抗性,初步证明通过非对称体细胞杂交技术已将外源抗性基因转入花椰菜中.实验表明UV辐射处理,导致再生植株中供体遗传信息的部分丢失或者染色体在不同程度上的消减,获得了花椰菜与黑芥的非对称体细胞杂种,但UV的剂量效应不明显.     

甘蓝热胁迫叶片细胞的超微结构研究

高温胁迫引起植物体损伤是很常见的,人们已从多方面探讨高温胁迫对植物的影响,主要工作集中在生理生化、膜结构、热激蛋白及作物产量等方面［１—４］,超微结构的变化也有少量报道［５—７］。但目前要建立一个高温对植物体影响的模式还比较困难。本文探讨了甘蓝不同耐热品种叶片细胞超微结构在热胁迫后的差异,目的是建立植物耐热程度的细胞学指标,为育种工作者选育耐热性品种提供细胞学依据。材料和方法试验材料为甘蓝（Ｂｒａｓｓｉｃａｏｌｅｒａｃｅａｖａｒ．ｃａｐｉｔａｔａＬ．）耐热品种“夏光甘蓝”和感热品种“京丰甘蓝”。…     

皱叶甘蓝的原生质体培养与植株再生

皱叶甘蓝(Brassica oleracea L. var. subauda)“SA61”(SV)的叶及下胚轴分离的原生质体在 MS_1(修改的MS)培养基上细胞壁再生和分裂启动较快。叶原生质体在 DPD_1(修改的 DPD)培养基上获得了最高的分裂率和植板率;下胚轴原生质体在MS_1上获得最佳的培养效果。叶原生质体培养3—4天后见到一次分裂;下胚轴原生质体在48小时左右即可发生一次分裂。原生质体培养 20—30天后形成肉眼可见的微愈伤颗粒,40天左右即可达1mm大小。在7种不同培养基上增殖微愈伤组织,MB_2、MB_3表现了优良的效果。在MS_2培养基上的芽分化效果最为理想。在不加任何激素的MS培养基上诱导生根,2周后得到再生植株。     

FLOWER DEVELOPMENT IN DIOECIOUS SPINACIA OLERACEA (CHENOPODIACEAE)

Spinacia oleracea (Chenopodiaceae) is a potential model system for studies of mechanisms of sex expression and environmental influences on gender in dioecious species. Development of the male and female flowers and inflorescences of spinach were studied to determine when the two sex types can be distinguished. We found that female inflorescence apices are significantly larger than those of the male. Flower primordia are similar in size prior to perianth initiation, but the male primordia develop at a faster rate. Another distinguishing feature at this early stage is the larger bract subtending the female primordium. The two flower types become readily distinguishable when the perianth initiates. Male flowers produce four sepals and four stamens in a spiral pattern in close succession. Female flowers produce two alternate perianth parts that enlarge somewhat before the gynoecium becomes visible. There are no traces of gynoecia in male flowers or of stamens in female flowers. We propose that plant sex type is determined before inflorescence development, prior to or at evocation.     

热胁迫下不结球白菜和甘蓝叶片组织结构的变化

利用显微及扫描电镜方法,研究不结球白菜及甘蓝的耐热品种和感热品种种在高温（３８－３９℃）胁迫下,叶片表皮和组织结构的差异。结果如下：耐热品种叶片下表皮比感热品种气孔频度高,气孔体积小且开张度小。耐热品种部分气孔呈关闭状态,而感热品种气孔基本上呈开放状态。显微结构观察到耐热品种叶肉组织细胞排列紧密,叶脉的维管束发达,特别是木质部的导管数量多且孔径大。而感热品种相比于耐热品种叶肉细胞排列疏松,维管束相     

通过PEG法转化甘蓝获得转基因植株

通过PEG法将外源基因导入甘蓝(Brassica oleracea L.)下胚轴原生质体。以潮霉素和卡那霉素进行筛选,均成功地得到了抗性愈伤组织。对于潮霉素抗性愈伤组织,其绝对和相对转化频率分别为4.1×10~(-4)和1％～3％,在分化培养基上,抗性愈伤组织能够分化出芽。诱导生根后进行移栽,生长状况良好。Southem blotting分析表明外源基因已插入到植物细胞基因组中。对影响转化的一些因素进行了探讨。