Mechanism of Resistance in Mungbean [Vigna radiata (L.) R. Wilczek var. radiata] to bruchids, Callosobruchus spp. (Coleoptera: Bruchidae)

Abstract

Mungbean [Vigna radiata (L.) R. Wilczek var. radiata] is an important pulse crop in Asia, and is consumed as dry seeds and as bean sprouts. It is an excellent source of digestible protein. Bruchids [Callosobruchus chinensis (L.) and Callosobruchus maculatus (F.)] are the important pests of mungbean and cause damage in the field and in storage. Bruchid infestation reduces the nutritional and market value of the grain and renders seeds unfit for human consumption, agricultural and commercial uses. These pests are controlled mainly by fumigation with highly toxic chemicals such as carbon disulfide, phosphene, and methyl bromide, or by dusting with several other insecticides, which leave residues on the grain, thus, threatening food safety. Some plant-based extracts have been found useful in controlling bruchids, but are not fully successful due to their short-term activity, rapid degradability, and potentially negative effect on seed germination. Although some wild sources of bruchid resistance in mungbean have been reported, which have been used to develop bruchid- resistant lines, undesirable genetic linkages threaten the proper exploitation of genetic diversity from wild germplasm into commercial cultivars. Further, biotype variation in bruchids has rendered some mungbean lines susceptible that otherwise would have been resistant to the pest. Host plant resistance is a cost-effective and a safe alternative to control bruchids in mungbean and is associated with morphological, biochemical, and molecular traits. These traits affect insect growth and development, thereby, reduce the yield losses by the pests. Understanding the defense mechanisms against insect pests could be utilized in exploiting these traits in crop breeding. This review discusses different traits in mungbean involved in defense against bruchids and their utility in pest management. We also highlight the breeding constraints for developing bruchid-resistant mungbean and how can these constraints be minimized. We further highlight the importance of supporting conventional breeding techniques by molecular techniques such as molecular markers linked to bruchid resistance.

QTL Mapping of Resistance to Bean Weevil in Common Bean

“…In eastern and southern Africa, farmers mix charcoal or wood ash with seed in storage to control weevils. Though effective, chemical control is less common in Africa because small-scale farmers cannot afford the pesticides and because there are food safety concerns associated with chemical control (War et al, 2017). Storing seed in cold rooms at 4 to 5°C can also be used to control weevils, but it is rarely used in Africa because most farmers do not have access to cold storage.…”

“…Pesticides are often applied in the form of powder to the seed in storage. Though effective, chemical control is less common in Africa because small-scale farmers cannot afford the pesticides and because there are food safety concerns associated with chemical control (War et al, 2017).…”

Post-harvest evaluation of selected inbred lines to maize weevil Sitophilus zeamais resistance

“…These differences in the resistance of the maize varieties indicate the inherent ability of the studied lines to resist S. zeamais attack. The resistance could either be due to antibiosis as a result of biochemical compounds which are toxic to insects or physical factors such as grain hardness (Garcia-Lara et al, 2004;Siwale et al, 2009;War et al, 2017). Resistance can also be attributed to pericarp surface texture, nutritional factors such as amylose, lipid and protein content (Dobie, 1974;Tipping et al, 1988;Tefera et al, 2013) or non-nutritional factors, especially phenolic compounds (Serratos et al, 1987;Tefera et al, 2013).…”

Biochemicals Associated With Callosobruchus Chinensis Resistance in Soybean.

“…The most environmentally friendly and cost effective method especially in the developing world to control the bruchids would be the use of resistant varieties. Resistance to seed damage by bruchids is conferred by both physical and chemical factors of the seeds (War et al, 2017). Soybean has been reported to contain and produce biochemicals that make it fairly resistant to insect pests.…”

“…The results indicate that there is an array of compounds found in seeds that act either additively or synergistically against bruchids. They act either directly on bruchid through antibiosis or develop the non-preference for insects feeding on the seeds (War et al, 2017). The secondary metabolites serve to reduce or destroy the palatability of the plant in which they are produced.…”