The cultivated Gossypium spp. (cotton) represents the single most important, natural fiber crop in the world. In addition to its fiber, the oil and protein portion of the cottonseed also represents significant economic value. To protect the worldwide economic value of cotton fiber and cotton byproducts, coordinated efforts to collect and maintain cotton genetic resources have increased over the last 100 yr. The classified genetic resources of cotton are extensive and include five tetraploid species in the primary gene pool, 20 diploid species in the secondary gene pool, and 25 diploid species in the tertiary gene pool. This report provides information on the status and contents of eight major cotton germplasm collections present across the world. Based on the findings of this report, a number of classified Gossypium species are not maintained in these collections, and several are underrepresented and vulnerable to extinction. This report presents several critical challenges and opportunities facing international efforts to enhance and preserve the world's Gossypium genetic resources. Multinational communication and collaboration are essential to protect, secure, and evaluate the global cotton germplasm resources. Without global, collaborative efforts, the rarest and most unique cotton germplasm resources are vulnerable to extinction.
Sclerotium rolfsii-caused stem and pod rots are major constraints to groundnut production in many groundnut-growing regions, and pose a serious threat to post-rainy and summer season groundnuts in expanding irrigated production systems. Considerable research has been carried out on the management of these diseases. The most relevant literature is reviewed and future research strategies are indicated.
Preharvest seed infection by Aspergillus flavus and aflatoxin contamination in selected groundnut genotypes (four A. flavus-resistant and four A. flavus-susceptible) were examined in different soil types at several locations in India in 1985-1990. Undamaged mature pods were sampled at harvest and seed examined for A. flavus infection and aflatoxin content in two or more trials at ICRISAT Center on light sandy soils and red sandy loam soils (Alfisols), and on Vertisols, at Anantapur on light sandy soils, and at Dharwad and Parbhani on Vertisols. Rainy season trials (1985-1989) were all rainfed. Post-rainy season trials were irrigated; late-season drought stress (90 days after sowing (DAS) until harvest at 125 DAS) was imposed in the 1987/88 and 1989/90 seasons. A. flavus infection and aftatoxin contamination levels were much lower in seed of all genotypes from Vertisols than in seed from Alfisols across locations and seasons. Vertisols also had significantly lower populations of A. flavus than Alfisols. There were no marked differences between light sandy soils and red sandy loam soils (Alfisols) in respect of seed infection by A. flavus and aflatoxin contamination. Significant interactions between genotypes and soil types were evident, especially in the A. flavus-susceptible genotypes. Irrespective of soil types, A. flavus-resistant genotypes showed lower levels of seed infection by A. flavus and other fungi than did A. flavus-susceptible genotypes. The significance of the low preharvest aflatoxin risk in groundnuts grown on Vertisols is highlighted.
A 3‐year study was made on genetic variability of seed oil content and seed index with 20 wild species, two cultivated species and six perennial races of Gossypium arboreum cotton maintained at the Central Institute for Cotton Research, Nagpur, India. The mean seed oil content varied from 10.26 to 22.89% in 22 species of Gossypium and six races of G. arboreum. In this material the weight of delinted seed varied from 43.33 to 54.54 mg/seed. The highest seed oil content was recorded in the species G. lobatum followed by G. harknessii. On average, for both traits, the means were higher for G. arboreum and its races. However, G. africanum and G. harknessii reached the level of G. arboreum and its races for seed weight, while five wild species surpassed the best races and G. arboreum in seed oil content, among them was G. harknessii. To breed simultaneously for seed oil content and seed weight, crosses between races of G. arboreum and wild species of Gossypium seem to be promising.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.