Combining ability for yield,protein and oil of peanut lines from South American centers of diversity

Summary Ten peanut (Arachis hypogaea L.) lines, two from each of five centers of diversity in South America, and the F₂ generation of all possible crosses among them were used to characterize the variation for yield, fruit and seed traits and protein and oil content and to determine the breeding potential of the parents. Two of the parental lines belong to subspecies hypogaea and the other eight to subspecies fastigiata.Several crosses gave heterotic responses for yield. The parents of the crosses with significant heterosis generally came from different centers of diversity.Variation among both general and specific combining abilities was significant for all traits with the exception of the SCA estimate for protein percent. The component of variation for GCA was larger than the SCA component for all traits.A Spanish line and a Valencia-like intermediate line from the Guarani region had the highest GCA effects for fruit yield, seed yield and meat content and transmitted consistently their characteristics to their F₂ progeny. Some lines showed significant but small maternal effects for oil, protein and oil + protein percent. Differences between reciprocal crosses were significant for fruit length, fruit weight and oil + protein percent.A significant portion of the variation among crosses was explained by differences among parental lines within centers of diversity. This supports the fact that centers are founded because of the diversity of the peanuts grown there.The performance of parental lines per se was useful in predicting the performance of the lines in hybrid combination for all traits except fruit yield.Paper number 6141 of the Journal Series of the North Carolina Agricultural Research Service (USA). This work was partially supported by CSRS Research Agreement 701-15-51.     

Makulu red—A ‘Green Revolution’ groundnut variety?

Summary The history and potentials of a high yielding groundnut variety has been described.     

Studies on Maize-Legume Intercropping and their Residual Effects on Soil Fertility Status and Succeeding Crop in Upland Situation

To examine the advantages of cereal-legume intercropping system with maize as main crops, field studies conducted for two years on sandy upland loamy soils in Bihar plateau, India, indicated maize-groundnut as the best system. Yield advantages were noticed between 22–44 % over sole maize cropping. Different production indices largely indicated the same pattern in ranking intercropping treatments. Of the other legumes used, mung also showed potential whereas cowpea and soyabean did not. Increasing cropping intensities through use of interspace by legume did not significantly reduce maize yield, particularly in combination with groundnut and mung. Soil nitrogen enrichment through legume cultivation could be noted through examination of soil test values and yield of succeeding wheat crop. Wheat, however, did not show its promise as a follow-up crop without input of water and fertilizer.     

Variation in a wild groundnut species, Arachis duranensis Krapov. & W.C. Gregory

Forty-two accessions of Arachis duranensis, a wild groundnut species that has been reported as a source of resistance to several groundnut diseases, were studied for 30 quantitative traits including total protein content, oil content, and reaction to groundnut rust. Protein profiles were also investigated for variation at the molecular level. Principal component analysis was applied to 28 traits that showed significant variation. Of these, only five characters, namely, height of the main stem, length of apical leaflet on the main stem, length of isthmus between pods, width of seed, and reaction to groundnut rust, accounted for more than 61.4% of the total variation. Protein profiles of these accessions were broadly similar, except some accessions which differed in few bands. The importance of these variations in strategies for germplasm collection and breeding is discussed.Submitted as Journal Article No. 1507 by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru P.O. 502 324 A.P. India.     

5种药剂对花生青枯病的防治效果

[目的]筛选花生青枯病的防治药剂.[方法]通过小区试验研究了5种药剂对花生青枯病的防治效果.[结果]20％青枯灵粉剂、72％农用链霉素粉剂、50％氯溴异氰尿酸粉剂、20％恶霉灵水剂、木霉菌剂5种药剂对花生青枯病均有一定的防治效果,但差别不大,其中用木霉菌剂4.5 kg/hm2+水22.5 kg/hm2拌种后立即播种,对青枯病的防治效果可达41.85％.[结论]试验结果为青枯病的防治提供了参考.     

Path analysis and percentage contribution of different growth characters to pod yield of groundnut (Arachis hypogaea L.) at Kadawa,Sudan savanna,Nigeria

Irrigated trials were conducted during the dry seasons of 2004, 2005 and 2006 at the Irrigation Research Station of the Institute for Agricultural Research (IAR), Nigeria, to study the performance of three groundnut (Arachis hypogaea L.) varieties as affected by basin size and plant population. Treatments consisting of three basin sizes (3 × 3, 3 × 4 and 3 × 5 m), three plant populations (50,000, 100,000 and 200,000 plants ha^?1) and three varieties (Samnut 11, Samnut 21 and Samnut 23), were laid out in a split-plot design with factorial combination of population and variety assigned to the main plots and basin sizes to the subplots. Plant height exhibited the highest positive (p ≤ 0.05) effect of 0.3993, 0.5124, 0.6296 and 0.5897, followed by total dry matter (0.2339, 0.3329, 0.4040 and 0.4197) and number of branches (0.1118, 0.0181, 0.0416 and 0.1541) in the three years and when combined. Path coefficient analysis revealed that among the growth characters selected, plant height made the highest positive contribution of 34.77% to pod yield of groundnut, followed by total dry matter with a positive contribution of 17.46%, suggesting plant height was the most critical growth parameter for determining yield of groundnut under irrigation.     

Dry Matter,Nitrogen, Phosphorous,and Potassium Partitioning,Accumulation, and Use Efficiency in Transgenic Cotton-Based Cropping Systems

A better understanding of the fate of nutrients in transgenic cotton (Gossypium hirsutum L.) fields will improve nutrient efficiencies, will optimize crop growth and development, and may help to enhance soil quality. A study was made to evaluate and quantify the effect of cropping system [sole cotton and groundnut (Arachis hypogaea) intercropping with transgenic cotton] and nitrogen (N) management [control (0N), 100% recommended dose of nitrogen (RDN) through urea, substitution of 25% RDN through farmyard manure (FYM), and substitution of 50% RDN through FYM] on dry matter (DM) and nutrient partitioning and accumulation by transgenic cotton and groundnut at New Delhi during 2006–2007. Soil and plant samples were collected and analyzed at 60, 90, and 120 days after sowing and at harvest. Results revealed that intercropping of groundnut with cotton did not significantly affect DM and nutrient partitioning in cotton, but residual soil fertility in terms of potassium permanganate (KMnO₄) N showed an improvement in contrast to Olsen's P and ammonium acetate (NH₄OAc)–exchangeable K over sole cotton. At harvest, of total DM assimilated, leaves constituted 10–20%, stem 50%, and reproductive parts of cotton accounted for the rest. For each kilogram of seed cotton produced, the crop assimilated 61 g of N, of which 23 g was partitioned to harvested seed cotton. Substitution of 25% RDN through FYM, being on par with 100% RDN through urea, recorded greater DM, nutrient uptake in different parts of cotton, agronomic N-use efficiency (9.5 kg seed cotton kg N^?1), and apparent N recovery (83.3%) over 50% RDN substitution through FYM and control. The control, being on par with 50% RDN substitution through FYM, recorded significantly greater DM and nutrient uptake by intercropped groundnut over other treatments. Apparent N and potassium (K) balance at the end of study was negative in all treatments; however, the actual change in KMnO₄ N was positive in all the treatments except control. Our study suggests that intercropping of groundnut with transgenic cotton and substitution of 25% dose of N through FYM is sustainable in tropical countries.     

Some Hydrolases and Their Involvement in Insecticide Resistance

Abstract

Virus diseases are an important factor worldwide in crop production losses. Correct diagnosis of a disease is essential and in developing countries in the absence of modern facilities virologists regard infectivity tests as an important tool in identifying viruses. However compared with progress in other areas of plant virology infectivity assays lag behind. These tests should be carried out under optimum environmental conditions to permit symptom development. Environmental conditions should be standardised. Results of infectivity tests should be interpreted in relation to variation in the environment and the use of a known cultivar and its source. The use of an indicator host relates indirectly with variation in the environment and consequently symptom development. A suitable host must be used if the virus is to initiate infection. Plants used as indicator hosts must be genetically identical and from the same origin. Sensitive hosts are required to index seed batches in a well organised seed certification programme. There is a need for international seed and serum centres in strategic regions among developing countries and close collaboration between virologists to list genetically identical test plants for infectivity assays under their own conditions. Other factors to improve identification include an understanding of insect vectors. When used properly these tests can play a significant role in identification of virus strains and screening for resistance against virus diseases of economically important cash and food crops.     

Biocontrol strain of Bacillus subtilis AF 1 rapidly induces lipoxygenase in groundnut (Arachis hypogaea L.) compared to crown rot pathogen Aspergillus niger

Metabolic products of polyunsaturated fatty acids have been variously implicated in control of microbial pathogens. Induced resistance has been shown as one of the mechanisms of biological control by plant growth promoting rhizobacteria (PGPR). This paper reports a significant lipoxygenase (LOX) activity in groundnut seedlings with production of 13-hydroperoxyoctadecadienoic acid (13-HPODE) and 13-hydroperoxyoctadecatrienoic acid (13-HPOTrE) as major products with linoleic acid (LA) and -linolenic acid (ALA), respectively. Both the hydroperoxides are inhibitory to the growth of Aspergillus niger as measured in micro titer plates. Ours is the first report on induction of LOX activities in groundnut on treatment with a PGPR strain Bacillus subtilis AF 1, and with crown-rot pathogen, A. niger. Treatment with B. subtilis AF 1 enhanced LOX levels in groundnut similarly but earlier to A. niger – treatment. This induction of LOX during activation of growth and pathogen infection was discussed in light of the reported involvement of LOX both in growth and development as well as in plant-pathogen interaction, particularly induced disease resistance.     

花生单粒种子脂肪酸含量的气谱快速无损测定(英文)

描述了一种利用5～20mg花生种子组织测定花生8种脂肪酸的方法。于室温下制备用于色谱分析的样品耗时35min,气相色谱分析则需要18min。研究结果证实,本法准确性高,重复性较好,可满足花生遗传育种研究中对种子无损取样及基因聚合育种需要,将为花生脂肪酸成分的遗传改良提供便利。