Person:
Krishna, G.

Profile Picture
Email Address
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
Krishna
First Name
G.
Name
Krishna, G.

Filters

2011 - 20173
Reset filters

Settings

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Genomic regions associated with root traits under drought stress in tropical maize (Zea mays L.)
    (Public Library of Science, 2016) Zaidi, P.; Seetharam, K.; Krishna, G.; Krishnamurthy, L.; Gajanan, S.; Babu, R.; Zerka, M.; Vinayan, M.T.; Vivek, B.
    An association mapping panel, named as CIMMYT Asia association mapping (CAAM) panel, involving 396 diverse tropical maize lines were phenotyped for various structural and functional traits of roots under drought and well-watered conditions. The experiment was conducted during Kharif (summer-rainy) season of 2012 and 2013 in root phenotyping facility at CIMMYT-Hyderabad, India. The CAAM panel was genotyped to generate 955, 690 SNPs through GBS v2.7 using Illumina Hi-seq 2000/2500 at Institute for Genomic Diversity, Cornell University, Ithaca, NY, USA. GWAS analysis was carried out using 331,390 SNPs filtered from the entire set of SNPs revealed a total of 50 and 67 SNPs significantly associated for root functional (transpiration efficiency, flowering period water use) and structural traits (rooting depth, root dry weight, root length, root volume, root surface area and root length density), respectively. In addition to this, 37 SNPs were identified for grain yield and shoot biomass under well-watered and drought stress. Though many SNPs were found to have significant association with the traits under study, SNPs that were common for more than one trait were discussed in detail. A total 18 SNPs were found to have common association with more than one trait, out of which 12 SNPs were found within or near the various gene functional regions. In this study we attempted to identify the trait specific maize lines based on the presence of favorable alleles for the SNPs associated with multiple traits. Two SNPs S3_128533512 and S7_151238865 were associated with transpiration efficiency, shoot biomass and grain yield under well-watered condition. Based on favorable allele for these SNPs seven inbred lines were identified. Similarly, four lines were identified for transpiration efficiency and shoot biomass under drought stress based on the presence of favorable allele for the common SNPs S1_211520521, S2_20017716, S3_57210184 and S7_130878458 and three lines were identified for flowering period water-use, transpiration efficiency, root dry weight and root volume based on the presence of favorable allele for the common SNPs S3_162065732 and S3_225760139.
    Publication
  • Thumbnail Image
    Use of genomic estimated breeding values results in rapid genetic gains for drought tolerance in maize
    (Crop Science Society of America, 2017) Vivek, B.; Krishna, G.; Vengadessan, V.; Babu, R.; Zaidi, P.; Kha, L.Q.; Mandal, S.S.; Grudloyma, P.; Takalkar, S.; Krothapalli, K.; Singh, I.S.; Ocampo, E.T.M.; Fan, X.M.; Burgueño, J.; Azrai, M.; Singh, R.P.; Crossa, J.
    More than 80% of the 19 million ha of maize (Zea mays L.) in tropical Asia is rainfed and prone to drought. The breeding methods for improving drought tolerance (DT), including genomic selection (GS), are geared to increase the frequency of favorable alleles. Two biparental populations (CIMMYT Asia Population 1 [CAP1] and CAP2) were generated by crossing elite Asian-adapted yellow inbreds (CML470 and VL1012767) with an African white drought-tolerant line, CML444. Marker effects of polymorphic single-nucleotide polymorphisms (SNPs) were determined from testcross (TC) performance of F2:3 families under drought and optimal conditions. Cycle 1 (C1) was formed by recombining the top 10% of the F2:3 families based on TC data. Subsequently, (i) C2[PerSe_PS] was derived by recombining those C1 plants that exhibited superior per se phenotypes (phenotype-only selection), and (ii) C2[TC-GS] was derived by recombining a second set of C1 plants with high genomic estimated breeding values (GEBVs) derived from TC phenotypes of F2:3 families (marker-only selection). All the generations and their top crosses to testers were evaluated under drought and optimal conditions. Per se grain yields (GYs) of C2[PerSe_PS] and that of C2[TC-GS] were 23 to 39 and 31 to 53% better, respectively, than that of the corresponding F2 population. The C2[TC-GS] populations showed superiority of 10 to 20% over C2[PerSe-PS] of respective populations. Top crosses of C2[TC-GS] showed 4 to 43% superiority of GY over that of C2[PerSe_PS] of respective populations. Thus, GEBV-enabled selection of superior phenotypes (without the target stress) resulted in rapid genetic gains for DT.
    Publication
  • Thumbnail Image
    Addressing climate change effects and meeting maize demand for Asia
    (GMRI, 2011) Zaidi, P.; Babu, R.; Cairns, J.E.; Jeffers, D.P.; Kha, L.Q.; Krishna, G.; Krishna, V.; Mcdonald, A.; Ortiz-Ferrara, G.; Palacios-Rojas, N.; Pixley, K.V.; Prasanna, B.M.; Rashid, Z.; Tadele Tefera; Tiwari, T.P.; Vinayan, M.T.; Vengadessan, V.; Fan, X.M.; Yunbi Xu; Weidong, C.; Zhang, S.; Vivek, B.
    This includes the extended summaries of the scientific presentations made during the 11th Asian Maize Conference held in Nanning, China, during 7-11 November 2011. The Conference is co-organized by the International Maize and Wheat Improvement Center (CIMMYT), and the Guangxi Maize Research Institute (GMRI), China. The theme of the workshop is "Addressing Climate Change Effects and Meeting Maize Demand for Asia". The 11th AMC brings together over 300 maize scientists, researchers and students from public and private sectors, including participants from several Asian countries, including Bangladesh, Bhutan, China, Colombia, India, Indonesia, Iran, Nepal, Philippines, Thailand, Turkey, Vietnam, besides Italy, Kenya, New Zealand, Mexico, Germany, Myanmar and the USA. The Conference features over 225 presentations, including keynote lectures, invited oral presentations, and poster presentations, besides scientific deliberations and discussions on maize in Asia. The extended summaries includes reviews and research papers on a diverse range of topics, including maize trends, challenges and opportunities in Asia, abiotic and biotic stresses affecting maize production, novel tools for maize improvement, conservation agriculture, nutritional enrichment of maize, participatory plant breeding, community-based seed production, public-private partnerships, maize value chains, policies and socio-economics relevant to Asia.
    Publication