Browsing by Author "G. Kalloo"

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Genetic diversity within the genus Solatium (Solanaceae) as revealed by RAPD markers
(2006) A.K. Singh; Major Singh; A.K. Singh; Rakesh Singh; Sanjeev Kumar; G. Kalloo
Random amplified polymorphic DNA (RAPD) technique was used as a tool for assessing genetic diversity and species relationships among 28 accessions of eggplant representing five species. Twenty-eight samples of eggplants were collected from different parts of the country. A total of 144 polymorphic amplified products were obtained from 14 decamer primers, which discriminated all the accessions. The value of Jaccard's coefficient ranged from 0.05 to 0.82. The similarity result indicates presence of high level of genetic diversity in eggplants and a dendrogram constructed by UPGMA method shows that S. incanum is closest to S. melongena followed by S. nigrum. Only one accession of S. nigrum and S. surattense was taken in the present study that showed grouping with each other. Genetically distinct genotypes identified using RAPD markers could be potential sources of germplasm for eggplant improvement.
'Kashi Madhu': A new muskmelon cultivar with high total soluble solids
(American Society for Horticultural Science, 2008) Sudhakar Pandey; Mathura Rai; H.C. Prasanna; G. Kalloo
'Kashi Madhu' (Cucumis melo L.) is a new muskmelon cultivar released for agroecological zone IV of India comprising the states of Uttar Pradesh, Uttaranchal, Delhi, Punjab, and Bihar. The cultivar was developed through selection from a local landrace. Plants bear androemonoecious flowers, round and yellow fruits with prominent green sutures and orange flesh color. The fruits become ready for first harvest in ≈90 days from seed sowing. The fruits have a distinct flavor and higher total soluble solids as compared with other cultivars recommended for cultivation in India after evaluation under different agroecological zones of India under the All India Coordinated Research Project on Vegetable Crops. The release of this cultivar was announced at the XIII meeting of Central Sub-committee on Crop Standard Notification and Release of Varieties for Horticultural Crops.
Tomato leaf curl Gujarat virus, a New Begomovirus Species Causing a Severe Leaf Curl Disease of Tomato in Varanasi, India
(American Phytopathological Society, 2003) S. Chakraborty; P.K. Pandey; M.K. Banerjee; G. Kalloo; C.M. Fauquet
The biological and molecular properties of Tomato leaf curl Gujarat virus from Varanasi, India (ToLCGV-[Var]) were characterized. ToLCGV-[Var] could be transmitted by grafting and through whitefly transmission in a persistent manner. The full-length genome of DNA-A and DNA-B of ToLCGV-[Var] was cloned in pUC18. Sequence analysis revealed that DNA-A (AY190290) is 2,757 bp and DNA-B (AY190291) is 2,688 bp in length. ToLCGV-[Var] could infect and cause symptoms in tomato, pepper, Nicotiana benthamiana, and N. tabacum when partial tandem dimeric constructs of DNA-A and DNA-B were co-inoculated by particle bombardment. DNA-A alone also is infectious, but symptoms were milder and took longer to develop. ToLCGV-Var virus can be transmitted through sap inoculation from infected tomato plants to the above-mentioned hosts causing the same symptoms. Open reading frames (ORFs) in both DNA-A and DNA-B are organized similarly to those in other begomoviruses. DNA-A and DNA-B share a common region of 155 bp with only 60% sequence identity. DNA-B of ToLCGV-[Var] shares overall 80% identity with DNA-B of Tomato leaf curl New Delhi virus-Severe (ToLCNDV-Svr) and 75% with ToLCNDV-[Lucknow] (ToLCNDV-[Luc]). Comparison of DNA-A sequence with different begomoviruses indicates that ToLCGV-[Var] shares 84% identity with Tomato leaf curl Karnataka virus (ToLCKV) and 66% with ToLCNDV-Svr. ToLCGV-[Var] shares a maximum of 98% identity with another isolate of the same region (ToLCGV-[MIr]; AF449999) and 97% identity with one isolate from Gujarat (ToLCGV-[Vad]; AF413671). All three viruses belong to the same species that is distinct from all the other geminivirus species described so far in the genus Begomovirus of the family Geminiviridae. The name Tomato leaf curl Gujarat virus is proposed because the first sequence was taken from an isolate of Gujarat, India.
Wild taxa of Okra (Abelmoschus Species): Reservoir of genes for resistance to biotic stresses
(International Society for Horticultural Science, 2007) B. Singh; Mathura Rai; G. Kalloo; S. Satpathy; K.K. Pandey
Eight Abelmoschus species occur in India. out of these, A. esculentus is the only known cultivated species. A. moschatus occur as wild species and is also cultivated for its aromatic seeds, while the rest six are truly wild types. The wild species occupy diverse habitats. The species A. ficulneus and A. tuberculatus spread over semi arid tracts of north and northwestern; A. crinitus, A. manihot and A. tetraphyllus and A. pungens are found in Tarai ranges and foot hills of Himalayas; A. angulosus, A. moschatus, A. tetraphyllus are widely distributed throughout western and eastern ghats and also peninsular tracts of south while A. crinitus and A. pungens are distributed in north eastern region of India. Assessions resistance to Yellow Vein Mosaic Virus (YVMV) in A. manihot, A. angulosus, A. crinitus and few land races of A. tetraphyllus, for okra Enation Leaf Curl Virus (oELCV) in A. crinitus, A. angulosus and A. manihot, for powdery mildew in A. tetraphyllus and A. angulosus, for Cercospora blight in A. crinitus, A. moschatus and A. angulosus and for fruit borer tolerant in A. tuberculatus have been identified at Indian Institute of Vegetable Research, Varanasi during last 14 years. High level of tolerance for mites and Jassids is found in A. angulosus and A. moschatus and A. crinitus, respectively, whereas, symptomless career to jassids has been observed in few lines of A. caillei. Wild species have not been fully utilized in breeding programmes due to crossing barrier. Resistance to YVMV is not stable in the cultivated species and frequent breakdown of resistance have been observed in developed varieties so that there is an urgent need to adopt the non-conventional method of breeding programme with combination of biotechnological tools for development of pre breeding lines resistant to biotic stresses.