Visarada K.B.R.S.,Indian Institute of Millets Research |
Prasad G.S.,Indian Institute of Millets Research |
Royer M.,CIRAD - Agricultural Research for Development
Plant Biotechnology Reports | Year: 2016
Sweet sorghum is a climate smart crop with multiple uses. The crop is susceptible to attack by the spotted stemborer, Chilo partellus (Swinhoe). This causes deadheart formation, leading to lodging of plants and consequent high economic losses. Lack of stable sources of resistance make any genetic enhancement through breeding difficult. We report a study to build up host plant resistance using transgenic technology by introducing two different classes of Bt genes (cry1Aa and cry1B) into two elite sweet sorghum genotypes of India (SSV84 and RSSV9). We devised tissue culture methods to suit the genotypes of our interest, SSV84 and RSSV9, and employed two methods of genetic transformation: the particle bombardment and in planta method of Agrobacterium. Modification of in vitro culture methods involved subculture every 3 days in the initial stages of culture and the use of precultured embryos as target tissues. For the in planta method, a floral dip for 1 h in Agrobacterium suspension supplemented with l-cysteine and Tween-20 was used. Sixteen transgenic events were generated; inheritance, integration and stable expression of the transgenes till the T4 generation were confirmed. The amount of Bt Cry1Aa protein at 25–30 days of growth ranged from 24.8 to 72.8 ng/g of fresh leaf tissue. We recorded 78.4 % larval mortality, reduced leaf damage (3.0 out of 9.0) and reduced feeding (41.0 %) over the controls in insect feed assays. Stable inheritance and expression in the in planta-derived transgenics are presented. © 2016 Korean Society for Plant Biotechnology and Springer Japan
Rao V.T.,Regional Agricultural Research Station RARS |
Reddy P.S.,Indian Institute of Millets Research |
Reddy B.V.S.,Indian International Crops Research Institute for the Semi Arid Tropics
Sabrao Journal of Breeding and Genetics | Year: 2016
In all sorghum (Sorghum bicolor (L.) Moench) production systems, grain molds can reduce the yield and quality of short duration cultivars if they mature in wet and humid weather. This investigation was taken up to find out combining ability for grain mold resistance under 4 environmental conditions by studying 168 hybrids and their parents along with checks. The pooled analysis of variance for combining ability revealed significant differences due to environments, parents, hybrids and various interactions indicating the existence of wide variability in the material under study. The ratios of additive to dominance variances revealed that additive gene action was predominant for inheritance of grain mold resistance (Panicle Grain Mold Rating - PGMR). Among the parents, two A-lines ICSA 369 and ICSA 370 and six testers viz., IS 41675, ICSR 91011, ICSR 89058, PVK 801, GD 65028, GD 65055 in all the 4 environments were identified as a good general combiners for grain mold resistance. These parents can be utilized for the development of grain mold resistant hybrids. © Society for the Advancement of Breeding Research in Asia and Oceania (SABRAO) 2016.
Reddy P.S.,Indian Institute of Millets Research |
Reddy B.V.S.,Indian International Crops Research Institute for the Semi Arid Tropics |
Kumar A.A.,Indian International Crops Research Institute for the Semi Arid Tropics |
Sharma H.C.,Indian International Crops Research Institute for the Semi Arid Tropics
Indian Journal of Genetics and Plant Breeding | Year: 2015
Breeding for resistance to sorghum shoot fly in A1 CMS system has been only partially successful. To compare the alternate Cytoplasmic Male Sterility_(CMS) systems for shoot fly resistance, 72 hybrids produced by crossing 36 A-lines carrying six diverse cytoplasms namely, A1, A2, A3, A4(M), A4(G) and A4(VZM), each in six nuclear backgrounds with two common fertility restorers. The hybrids were evaluated during 2006 and 2007 rainy and post rainy seasons in shoot fly screening trials at ICRISAT. ANOVA indicated absence of overall cytoplasmic influence on dead hearts%. The general (GCA) and specific combining ability (SCA) estimates suggested that inheritance for deadhearts was governed by additive-type of gene action. For GCA effects, the A2 and A4(M) cytoplasms and for SCA effects, the A4(G) and A4(M) cytoplasms were superior over other cytoplasms. Overall, the A4(M) cytoplasm seemed to contribute to shoot fly resistance in hybrid combinations. However, use of all the six alternate cytoplasms should not increase the risk of shoot fly in commercial grain production. © 2015, Indian Society of Genetics and Plant Breeding. All rights reserved.
Ganapathy K.N.,Indian Institute of Millets Research |
Rakshit S.,Indian Institute of Millets Research |
Gomashe S.S.,Indian Institute of Millets Research |
Audilakshmi S.,Indian Institute of Millets Research |
And 2 more authors.
Plant Genetic Resources: Characterisation and Utilisation | Year: 2016
Knowledge on genetic diversity is necessary to determine the relationships among the genotypes, which allow the selection of individual accessions for crop breeding programmes. The present study aimed at assessing the extent and pattern of genetic diversity within a set of 251 sorghum genotypes using SSR markers. A total of 393 alleles were detected from the 251 genotypes, with the number of alleles ranging from 2 (Xcup11) to 24 (Sb5-206) and an average of 10.07 alleles per primer pair. Pairwise Wright's FST statistic and Nei's genetic distance estimates revealed that the race and geographical origin were responsible for the pattern of diversity and structure in the genetic materials. In addition, the analysis also revealed high genetic differentiation between the rainy and post-rainy sorghum groups. Narrow diversity was observed among the different working groups in the rainy (restorers and varieties) and post-rainy (varieties and advanced breeding lines) sorghum groups. Neighbour-joining and STRUCTURE analysis also classified 44 elite lines broadly into two distinct groups (rainy and post-rainy). However, limited diversity within the rainy and post-rainy sorghum groups warranted an urgent need for the utilization of diverse germplasm accessions for broadening the genetic base of the Indian breeding programme. The diverse germplasm accessions identified from the mini-core accessions for utilization in breeding programmes are discussed. Copyright © NIAB 2016