Inheritance of ‘domestication’ traits in bambara groundnut (Vigna subterranea (L.) Verdc.)

Controlled crosses in bambara groundnut were attempted between a range of thirty-six bambara groundnut landraces (thirty domesticated (V. subterranea var. subterranea) and six wild (V. subterranea var. spontanea)). Ten F₁ seed were produced. Of these, eight germinated producing F₂ populations. On seed set, four populations could be unambiguously confirmed as true crosses by F₃ seed coat colour. A single F₂ population, derived from a domesticated landrace from Botswana (DipC; female parent) crossed with a wild accession collected in Cameroon (VSSP11; male parent) was used to study a range of agronomic and domestication traits. These included; days to emergence, days to flowering, internode (fourth) length at harvest, number of stems per plant, leaf area, Specific Leaf Area (SLA), Carbon Isotope Discrimination (CID), 100 seed weight, testa colour and eye pattern around the hilum. On the basis of variation for internode length and stems per plant, 14 small F₃ families were selected and grown under field conditions to further investigate the genetic basis of the ‘spreading’ versus ‘bunched’ plant character, a major difference between wild and cultivated bambara groundnut. Results presented suggest that traits including leaf area, SLA, CID and 100 seed weight are controlled by several genes. In contrast, the variation for traits such as internode length, stems per plant, days to emergence and seed eye pattern around the hilum are likely to be under largely monogenic control. The results of this work are discussed in relation to the domestication of bambara groundnut.     

Genetic variation among Southern African cultivated peanut (Arachis hypogaea L.) genotypes as revealed by AFLP analysis

The amplified fragment length polymorphism (AFLP) technique, employing two different rare cutters, EcoRI and MluI in combination with the frequent cutter MseI, was used to assess genetic diversity and relationships among 21 closely related cultivated Southern African peanut genotypes. A dendrogram was constructed using Jaccard's coefficient and the UPGMA clustering method. Low levels of polymorphism (on average 2.78%) were detected. Results indicated that both EcoRI/MseI and MluI/MseIAFLP enzyme combinations efficiently detected polymorphism within closely related cultivated peanut, although the EcoRI/MseI enzyme combination detected more fragments per primer combination (on average 67.8) as opposed to29.7 by the MluI/MseI enzyme combination. All 21 genotypes could be uniquely distinguished from each other with a minimum of three MluI/MseI primer combinations. Genetic data correlated well with known species and pedigree data, dividing the 21 genotypes into two main groups corresponding to the two subspecies of Arachis hypogaea namely fastigiata and hypogaea. Divisions within the two main groups correlated with botanical types and pedigree data. This is the first report where MluI/MseI primer combinations were used on cultivated peanut and also the first successful detection of polymorphisms between closely related cultivated peanut genotypes worldwide. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effects of Transgenic Cotton-Based Cropping Systems and Their Fertility Levels on Succeeding Wheat Crop

Cotton–wheat is the second most important cropping system after rice–wheat in India and Pakistan, and is practiced on about 4.02 mha. By 2010, more than 6 million Indian farmers had adopted transgenic Bt cotton on 9.4 mha—almost 90% of the country’s total cotton area. There is a paucity of information on the effects of intercropping and integrated nitrogen (N)–management practices in transgenic Bt cotton on productivity, nutrient availability, and soil biological properties in the succeeding wheat crop in a cotton–wheat system. A study was made to evaluate and quantify the residual effect of two-tiered intercropping of cotton and groundnut with substitution of 25–50% recommended dose of nitrogen (RDN) of cotton by farmyard manure (FYM) on productivity and soil fertility in a cotton–wheat system at New Delhi during 2006–2008. Wheat following groundnut-intercropped cotton receiving 50% RDN substitution through FYM had significantly 5% greater grain yield than that after sole cotton. Residual soil fertility in terms of organic carbon (C), potassium permanganate (KMnO₄)-N, and dehydrogenase activity (14%) showed an improvement under cotton + groundnut–wheat system with substitution of 50% RDN of cotton by FYM. Apparent N balance as well as actual change in KMnO₄-N at wheat harvest was negative in most of the treatments, with greater loss (–58.1) noticed under pure stand of the cotton–wheat system with 100% RDN of cotton through urea. The study suggested that inclusion of legume and organic manure in transgenic Bt-cotton–wheat system is a sustainable practice for combating escalating prices of N fertilizers with environmental issues and instability of transgenic hybrids in south Asian countries.     

次氯酸钠对花生饼中黄曲霉毒素去毒效果的研究

把自然条件下产生黄曲霉毒素的花生饼作化学去毒处理，使用的脱毒剂为次氯酸钠，次氯酸钠用量分别为０．２５％、０．５０％和１００％，处理时间分别是２４、４８和７２ｈ。试验结果表明，次氯酸钠是一种有效的黄曲霉毒素脱毒剂，添加０．２５％次氯酸钠处理含有黄曲酶毒素的花生饼２４、４８和７２ｈ，分别使黄曲霉毒素总量减少９３．３２％、９５．５１％和９６．２７％；而添加１００％次氯酸钠处理不同时间的，则分别使毒素量下降９４．８２％、９３．８２％和９６．６５％。在本试验条件下，不同处理条件之间的脱毒效果差异不显著     

Fatty acid and amino acid composition of groundnut mutants

Groundnut mutants TG-8, TG-9, TG-17 and TG-18 induced by -irradiation differed in fatty acid composition from their parent Spanish Improved. All the mutants had lower linoleic and higher oleic than Spanish Improved. TG-18 had lower oleic and higher linoleic as compared with TG-8, TG-9 and TG-17. Palmitic acid in TG-18 and Spanish Improved was higher than other mutants. Oil stability as judged by oleic to linoleic ratio was substantially higher for mutants as compared with their parent.Amino acid composition of groundnut mutant proteins differed from Spanish Improved. In general mutants had higher contents of lysine, histidine, proline, phenylalanine and tryptophan and lower contents of threonine, serine and methionine. The first limiting amino acid was tryptophan in Spanish Improved, threonine in TG-8, TG-9 and TG-17 and Valine in TG-18. Essential amino acid contents for all except methionine, valine and threonine per grain flour were higher in all the mutants as compared with their parent.     

云南花生种质丰产性和品质性状的改良潜力

利用改良潜力公式推算云南省现有的 2 66份花生栽培种种质 ,花生的丰产性改良潜力大于品质性状的改良潜力。在花生种质丰产性改良潜力中 ,单株生产力改良潜力 >单株果数改良潜力 >百果重改良潜力。在品质性状的改良潜力中 ,油酸 /亚油酸比的改良潜力 >油酸的改良潜力 >亚油酸的改良潜力 >含油量的改良潜力。不同类型间改良潜力存在一定的差异     

15%毒死蜱颗粒剂(乐斯本)防治花生蛴螬药效分析

为了筛选出防治花生蛴螬高效、低残留药剂,对15%毒死蜱颗粒剂(乐斯本)防治花生蛴螬进行了药效对比及用量试验,发现1 000、1 500、2 000g/667m2防效高于30%毒死蜱.辛硫磷乳油(邦得)和辛硫磷灌墩处理,荚果被害率最低,分别为10.84%、9.78%、8.86%;按防虫效果比较,15%毒死蜱颗粒剂(乐斯本)1 500、2 000g/667m2的防效与30%毒死蜱.辛硫磷乳油灌墩处理效果均达90%以上,比辛硫磷灌墩处理分别提高39.91和40.37个百分点。15%毒死蜱颗粒剂(乐斯本)1 000g/667m2即可达到理想的防治效果,且成本最低,花生荚果产量最高,纯增值495.1元,比辛硫磷和邦得纯增值分别提高147.6元和8.6元。因此15%毒死蜱颗粒剂(乐斯本)可替代高毒农药,一次施药即可控制蛴螬的危害,可在生产上大面积推广应用。