Global Project 2

Coordinator: HC Sharma

Marker-assisted selection for enhanced resistance to insect pest and diseases

Description: Stem borers (Chilo, Busseola, and Diatraea) and are the major pests of grain sorghum worldwide, and cause annual estimated losses of over 350 million annually in the SAT. Sorghum midge (Contarinia sorghicloa) is a major pest in all sorghum growing regions. The progress in breeding for resistance to stem borers has been slow because of quantitative nature of gene action. The environment influences the expression of resistance therefore, it is important to identify QTL associated with resistance to these pests in order to accelerate the pace of development of cultivars with resistance to these pests for sustainable crop production.

Applied: Globally


Project Title: Mapping shoot-fly resistance in sorghum

Team Members: Folkertsma R, Hash CT, Reddy BVS, Sharma HC, and Chandra S

Partners: Pharbani Agricultural University, Dharwad Agricultural University

Description: Two RIL populations have been generated, segregating for shootfly resistance (BTx623×IS18551 and 296B×IS18551), with both populations having the same shootfly resistant sorghum breeding line IS18551. Both populations have been genotyped and phenotyped and QTL for traits associated with shoot fly resistance have been mapped. A number of these QTL were detected at similar locations in both populations.

Applied: SSR markers linked to QTL for dead heart incidence in RIL population BTx623×IS18551 are currently being used in marker-assisted breeding programs to transfer the QTL from IS18551 to shoot fly susceptible Indian sorghum breeding lines.

Project Title: Mapping head bug/grain mold resistance in sorghum

Team Members: Folkertsma R, Hash CT, Thakur RP, Sharma HC, Reddy BVS, and Rattunde EW

Description: This activity is not being worked on.

Project Title: Mapping Striga resistance in sorghum

Team Members: Folkertsma R, Hash CT, Jayashree B, and Rattunde EW

Partners: University of Hohenheim, Stuttgart, Germany ARTC, Wad Medani, Sudan NARI, Asmara, Eritrea KARI, Katumani, Kenya IER, Bamako, Mali

Description: QTL for Striga hermonthica resistance have been mapped in two mapping populations (N13×E36-1 and IS9830×E36-1) (Haussmann et al. 2004). The QTL detected in population N13×E36-1 are currently transferred to susceptible, farmer preferred sorghum varieties in East and West Africa using marker-assisted selection.

Applied: By 2007, the first lines derived from farmer-preferred sorghum varieties with S. hermonthica resistance QTL should be in the field for field-testing in east and West Africa.

Project Title: Mapping downy mildew resistance in pearl millet

Team Members: Hash CT and Thakur RP

Partners: University of Wales, Bangor National programs in Eritrea and Nigeria TNAU, CCS HAU, and AICPMIP in India

Description: QTL mapping based on screens of existing mapping population progeny sets against additional pathogen populations (now primarily of African origin and at UWB); SSR and RFLP-based marker-assisted backcrossing of selected QTLs into elite hybrid parental lines; marker-directed conventional greenhouse screening to backcross selected QTLs into elite hybrid parental lines; agronomic and disease reaction assessment of products

Applied: First cultivar release in 2005 in India, and later in Africa.
Application is underway at Patancheru.

Team Members: Sharma HC, Gaur PM, and Hoisington D

Partner: CSIRO, Perth, Western Australia

Description: Pod borer, Helicoverpa armigera, is the most important pest of chickpea and other field crops globally. It causes an estimated loss of $350 million in chickpea and over $2 billion in other crops in the SAT. Control of this pest has become difficult because of development of resistance to insecticides. Breeding for resistance has been slow because of the quantitative nature of gene action, and the levels of resistance are low to moderate. Therefore, it is important to identify the QTL associated with resistance to this pest for gene pyramiding and to develop cultivars with stable resistance to this pest.

Applied: Globally

Project Title: Mapping Ascochyta blight and Fusarium wilt resistance in chickpea

Team Members: Gaur PM, Pande S, and Hoisington D

Partners: Punjab Agricultural University, Ludhiana, India CSK Himachal Pradesh Krishi Vishwa Vidyalaya Hill Agriculture Research and Extension Centre, Dhaulakuan, Sirmour, Himachal Pradesh, India

Description: Ascochyta blight (AB) caused by Ascochyta rabiei (Pass.) Labr is the most important foliar disease of chickpea globally, causing yield losses of about US $260 million annually. It was not possible to develop chickpea varieties with high level of resistance to AB because only low to moderate levels of resistance is available in the germplasm and the resistance is controlled by several QTLs. Molecular markers linked to major AB resistance QTLs can greatly facilitate pyramiding of resistance genes from different sources. Several markers linked to major AB resistance QTLs have been reported. This activity aims at validation of these markers and use of selected markers in marker-assisted breeding of AB resistance.

Applied: Globally

Project Title: Mapping Fusarium wilt resistance in pigeonpea

Team Members: Hoisington D, Pande S, Saxena KB

Project Title: Mapping early/late leaf spot resistance in groundnut

Team Members: Waliyar F, Hoisington D, Upadhyaya HD, and Nigam SN

Description: Genotypic (using SSR markers) and phenotypic (by artificial inoculation with fungal agents under field conditions) evaluation of groundnut breeding populations, advanced breeding lines, interspecific derivatives for LLS and rust.



Project Title: Mapping Aflatoxin resistance in groundnut

Team Members: Waliyar F, Upadhyaya HD, Nigam SN, Hoisington D

Description: Genotypic and phenotypic evaluation of groundnut breeding populations, advanced breeding lines, interspecific derivatives for resistance to Aspergillus flavus

Exploitation of wild relatives of crops for increasing the levels and diversifying the basis of resistance to insect pests and diseases

Team Members: Sharma HC and Clements SL

Partners: CSIRO, Perth, Australia. USDA/Washington State University, Pullman, USA. Osmania University, Hyderabad.

Description: Pod borer, Helicoverpa armigera, is the most important pest of cereals, legumes, oilseeds, vegetables, and fruit crops. It causes an estimated loss of over $2 billion in the SAT despite application of $500 million worth of pesticides to control this pest. Its control has become difficult because of development of resistance to insecticides. Breeding for resistance has been slow because the levels of resistance are low to moderate. Therefore, it is important to increase the levels and diversify the basis of resistance to this pest by identifying wild relatives of crops with different mechanisms of resistance, and pyramid the resistance genes to develop cultivars with stable resistance to this pest.

Applied: In Asia, Australia, Africa, and North America.

Project Title: Introgression of genes conferring resistance to Helicoverpa from wild relatives of pigeonpea and chickpea

Team Members: Mallikarjuna N, Gaur PM , Sharma HC, and Upadhyaya HD

Partners: ARIs: Dr. H. Clarke-CLIMA, Australia Dr. Fred Muehlbauer, WSU- USA; Dr. M. Lulsdorf-Saskatoon, Canada. NARs: Dr. Sandhu, Ludhiana, India.

Description: Wild annual Cicer from the compatible gene pool, with resistance to AB, BGM (identified recently) and Helicoverpa were used in the crossing program. The derivatives are in different generations and some of them are being screened for the target diseases. Use of annual wild Cicer from the incompatible gene pool, the emphasis is on the development of technology for successful cross ability.

Applied: The products are for global use, and in all chickpea growing regions of the world.

Project Title: Wide hybridization for resistance to early/late leaf spots and Aflatoxins in groundnut

Team Members: Mallikarjuna N, E Monyo, and Waliyar F

Partners: Dr. S Tallury, NCSU-USA Dr. Manohar Rao, Osmania University, India (till 2004).

Description: Advanced generation interspecific derivatives are under ICRISAT, Patancheru, and field trials for LLS. The material will be screened for ELS in Africa. Early generation interspecific derivatives (using wild Arachis) are being generated, using new sources of resistance to ELS and LLS, to diversify the sources of resistance. Amongst the three wild Arachis (incompatible with cultivated species) with resistance to Aspergillus flavus colonization, one has been successfully crossed with cultivated species using embryo rescue and other interventions. The seeds when obtained in large numbers will be screened for Aspergillus flavus colonization and aflatoxin production.

Applied: Globally in all groundnut growing areas, especially in Africa and Asia

Transgenic resistance to insect pests and diseases

Project Title: Transgenic resistance to Helicoverpa in pigeonpea and chickpea

Team Members: Sharma KK and Sharma HC

Description: Pod borer, Helicoverpa armigera, is the most damaging pest of grain legumes, cereals, fiber, vegetable, and fruit crops. It causes losses of over 5 billion dollars, despite application of pesticides costing over 2 billion dollars annually. It has developed high levels of resistance to conventional pesticides, and therefore, it is important to develop alternative methods of pest control, including transgenic plants with resistance to this pest. It is in this context that we have undertaken the development of transgenic plants with resistance to this pest for use in integrated pest management and sustainable crop production.

The legume pod borer, Helicoverpa armigera, is the most important constraints for chickpea and pigeonpea production in the SAT. It causes an estimated loss of over US$ 1 billion annually. Currently, Helicoverpa management is heavily based on insecticides, leading to development of resistance in insect populations, destruction of non-target organisms, environment pollution, and toxicity hazards to human beings. Therefore, it is important to use alternate methods of pest control, of which host plant resistance is most relevant tactic under subsistence farming conditions in the SAT. The levels of resistance in the identified sources are low to moderate, and vary across seasons and locations. Therefore, it is important to undertake genetic transformation of pigeonpea and chickpea with genes having insecticidal properties. These include genes derived from Bacillus thuringiensis such as cry1Ab, cry1Ac, cry2Aa and other that may become available in due course to make HPR a viable proposition for the management of this difficult to control pest, and study the influence of transgenic plants on the parasitoid, Campoletis chlorideae. Tissue culture and transformation protocols have been standardized for chickpea and pigeonpea. Toxins from Bacillus thuringiensis, soybean trypsin inhibitor, and lectins have been bio-assayed for their effectiveness against Helicoverpa in artificial diet, and in transgenic tobacco plants. Chickpea plants with Bt genes have been developed, and need to be characterized for integration of the genes, and effectiveness against Helicoverpa under lab, greenhouse, and field conditions.

Team Members: Sharma KK and Sharma HC

Team Members: Sharma KK, Waliyar F, and Lava Kumar P

Description: Natural sources of resistance to the diseases caused by Indian peanut clump virus (IPCV), Peanut clump virus (PCV), Peanut bud necrosis virus (PBNV), Tobacco streak virus (TSV) and groundnut rosette are not available, or if available, not adequate to full protect the crop under endemic conditions. Therefore, resistance to these viruses is being engineered through transgenic approach using the virus-derived (coat protein or replicase) genes for effective management of these endemic diseases of groundnut in Asia and Sub-Saharan Africa. This project is also engineering groundnut for inducing resistance to fungi (Aspergillus flavus and foliar disease agents) using Chitinase and Glucanase genes.

Team Members: Sharma HC, Romies, J, and Sharma KK

Project Title: Diagnostic tools for mycotoxins and viruses

Team Members: Waliyar F, Lava Kumar P

Description: This project is dealing with development of rabbit-polyclonal antibodies against plant viruses and mycotoxins (especially aflatoxins) to develop simple and cost-effective serological diagnostic assays; and development of nucleic acid-based diagnostic assays (PCR, RT-PCR and Dot-blot hybridization) for sensitive detection of plant viruses and evaluation of virus-transgenic plants.

Project Title: Characterization of pigeonpea sterility mosaic virus isolates and development of diagnostic tools

Team members: Lava Kumar P, Waliyar F, and Saxena KB

Description: Sterility mosaic disease (SMD), caused by Pigeonpea sterility mosaic virus (PPSMV) transmitted by an eriophyid mite, Aceria cajani, is a major constraint on pigeonpea production in the Indian subcontinent. Biodiversity in PPSMV isolates is responsible for breakdown of SMD resistance. This project seeks to characterize the important PPSMV isolates occurring in India, and develop serological and/or nucleic acid-based diagnostic tools for its detection.

Project Title: Up-scaling Trichoderma for biocontrol of Aspergillus

Team Members: Waliyar F , Thakur RP

Description: This project is evaluating a large number of isolates of Trichoderma (>250) for their antagonism against a toxigenic strain of Aspergillus flavus to select potential isolates for bio-management of A. flavus in the farmer's fields. Two Trichoderma isolates T. viride (Tv 47) and T. harzianum (Th 23), which has significantly reduced A. flavus infection is being studied for their potential for large-scale application and attempts are being made to understand the mechanisms involved.