Introgression of disease resistance genes from Arachis kempff-mercadoi into cultivated groundnut

Arachis kempff‐mercadoi is a wild species from the section Arachis. All kempff‐mercadoi accessions originate from the Santa Cruz province of Bolivia and they represent Arachis species with the A genome. From molecular analysis it was found that although cultivated A. hypogaea is made up of A and B genomes, A. kempff‐mercadoi may not be as closely related to it as are some of the other A genome species. Arachis kempff‐mercadoi is of interest because it has multiple disease resistance. It was crossed with a Spanish A. hypogaea cultivar which is susceptible to foliar diseases and to the insect pest Spodoptera litura. The success rate of the cross A. hypogaea (2n = 40) ×A. kempff‐mercadoi (2n = 20) was very low, but it could be increased by culturing immature seeds in vitro. Although the hybrids were triploids, a few fertile pollen grains were obtained due to the formation of restitution nuclei in the F₁ plants. Interspecific derivatives at the BC₂F₂ generation were scored for early leaf spot, late leaf spot and to Spodoptera damage. Screening results showed that 29% of the derivatives had both early and late leaf spot resistance and that less than 5% of the derivatives had resistance to both the foliar diseases and to Spodoptera.     

Genetics of induced dwarf mutants in pearl millet,Pennisetum americanum (L.)Leeke

Summary Inheritance pattern of seven dwarf mutants revealed each of them to be controlled by a single recessive gene. Tests for allelism indicated existence of two groups of dwarfs, group 1 comprising six mutants and group 2 a single dwarf. The dwarfs of group 1 were found to be allelic to D₂ of the dwarf types already known in this crop and the dwarf of group 2 was allelic to D₁ of these types.Botany Department, R.V.V.N. College, Dharanikota, India.     

Heterosis in growth and photosynthetic rate in hybrids of cotton

Summary The intraspecific (Gossipium hirsutum) and interspecific (G. hirsutum x G. barbadense) F₁ hybrids of cotton were found to exhibit a high degree of heterosis in the production of fruiting branches, number of bolls (fruits), yield of seed cotton and photosynthetic rates over the parent plants. The developing bolls of the hybrids had significantly higher weights than their parents until the 20th day after anthesis. The patterns of leaf area development among interspecific hybrids differed when compared with the parent plants. The photosynthetic rates of the hybrids were comparable with those of maize and sorghum and much higher than the average rate reported so far for the cotton plant.     

Genetics of some in vitro characters in pearl millet

Summary Genetics of four in vitro characters was studied using immature inflorescence-derived callus from four inbred lines. The number of genes controlling total callus quantity varied from 5–11, those for embryogenic(E) callus quantity from 4–7, for callus growth rate from 3–12 and those for regeneration frequency varied from 4–9 in the three segregating F₂ populations. Callus derived from the dwarf plants (d₂ d₂) was phenotypically distinguishable from that of the tall accessions. The association between d₂ locus and the in vitro characters was analysed using three different approaches. It is suggested that d₂ locus might be closely linked to majority of the loci governing E callus production.     

转双价广谱抗病基因创造甘蓝型油菜抗菌核病新品种的研究

菌核病严重威胁着我国长江中下游地区甘蓝型油菜的生产，几乎每年都会导致甘蓝型油菜的大面积减产。来自于烟草的葡聚糖酶(Glucanase)基因，其编码产物能降解真菌的细胞壁结构成分一葡聚糖。来自于烟草的植物蛋白AP24则属于细胞程序性死亡(PCD)的诱导蛋白，对多种真菌具明显抑制作用。前期已成功地将这两个广谱抗病基因导入甘蓝型油菜，并且通过表型鉴定，在T0和T1代检测到了核盘菌抗性。本实验对转基因T2代和T3代甘蓝型油菜进行分子鉴定和田间抗病性鉴定。经过PCR分子鉴定，从14个转基因T3代甘蓝型油菜株系中筛选到4个外源基因已经纯合的株系。对株系GA02—2的RT—PCR鉴定则进一步证明外源广谱抗病基因在RNA水平上的大量表达。田间抗性鉴定主要利用苗期离体叶接种和成株期茎杆插签接种这两种方法。结果表明，T2代转基因株系中有5个株系表现为抗病基因初步纯合，5个株系表现为隐性纯合，12个株系处于分离当中，其中株系GA02—2的抗病性鉴定结果与RT—PCR鉴定的结果吻合。18个T3代转基因甘蓝型油菜株系中有7个株系表现为抗性纯合，3个株系剖现为隐性纯合，其余8个株系基本上仍在分离中，其中株系GA02—2—1的抗病性鉴定结果与前面的分子鉴定以及上代的抗病性鉴定完全吻合。综合分子鉴定和抗病性鉴定结果，筛选出抗病效果良好的转基因纯合株系应用于抗病育种。     

Freeze preservation of gladiolus pollen

Viability and fertility profiles of cryopreserved gladiolus pollen from 7 cultivars have shown that it is possible to use cryogenic methods for conservation and management of the haploid gene pool in this species. There was no decline in pollen viability (in vitro) levels after 1 and 10 years of cryogenic storage. Field pollinations with cryogenic stored pollen induced capsule and seed set in varying capacities. Long-term cryogenic storage of gladiolus pollen could enhance breeding efficiency through better management of the haploid gene pool resources. Pollen parents could be made available throughout the breeding programme, ensuring guaranteed supply at the time of peak stigma receptivity. A pollen cryobank facility established for this species would increase genetic diversity conservation at the haploid stage.IIHR Contribution No. 112/93     

非热杀菌技术在食品中的应用(1)

非热杀菌是当代一类崭新的技术,它既有利于保持食品功能成分的生理活性,又有利于保持原料的色、香、味及营养成分。介绍了超高压杀菌(UHP)、超高压脉冲电场杀菌(PEF)、脉冲强光杀菌(PSL)、微波杀菌(MW)、放射线杀菌(RADIATION)、臭氧杀菌(OZONE)、生物保藏(Bio-conserve)和膜分离(FilmSeparation)技术在食品中的应用及其发展现状。     

The use of risk aversion in plant breeding; Concept and application

Summary Variance analysis is used to measure stability (inter-temporal) and adaptability (over space) components of variance with multilocation-multiyear sorghum yield data from India. Adaptability and stability were highly correlated. Only the stability component is relevant for farmers in their adoption decision. Measures of farmer's risk aversion are used to rank genotypes according to preferences which take account both of yield and stability. Since yield differences were large and risk aversion moderate, preference based rankings did not differ markedly from yield based rankings.     

燕麦β-葡聚糖的研究

综述了近年来国内外在燕麦β-葡聚糖领域的研究内容和成果,包括燕麦β-葡聚糖的分子结构、理化性质、生理功能及其制备和含量测定,并对燕麦β-葡聚糖今后的研究进行了展望。