Genetics of rate limiting disease reaction to Alternaria solani in Tomato     

E. S. Rao  A. D. Munshi  P. Sinha  Rajkumar 《Euphytica》2008,159(1-2):123-134

A study was conducted to understand the genetics of rate limiting disease reaction to Alternaria solani in tomato. The results from χ² analysis and Castle Wright estimation revealed that resistance is an oligogenic character controlled by two to few genes. In general, the results for predominant gene effects reveal that both additive and non-additive effects are involved in the inheritance of early blight resistance. The results for predominant gene effects obtained for various crosses studied are discussed along with their implications for improvement of this trait.  相似文献   

GENETICS. The Human Variome Project     

Cotton RG  Auerbach AD  Axton M  Barash CI  Berkovic SF  Brookes AJ  Burn J  Cutting G  den Dunnen JT  Flicek P  Freimer N  Greenblatt MS  Howard HJ  Katz M  Macrae FA  Maglott D  Möslein G  Povey S  Ramesar RS  Richards CS  Seminara D  Smith TD  Sobrido MJ  Solbakk JH  Tanzi RE  Tavtigian SV  Taylor GR  Utsunomiya J  Watson M 《Science (New York, N.Y.)》2008,322(5903):861-862

An ambitious plan to collect, curate, and make accessible information on genetic variations affecting human health is beginning to be realized.  相似文献   

Identification of two RAPD markers genetically linked to a recessive allele of a Fusarium wilt resistance gene in pigeonpea (Cajanus cajan L. Millsp.)     

H. Kotresh  B. Fakrudin  S. M. Punnuri  B. K. Rajkumar  M. Thudi  H. Paramesh  H. Lohithswa  M. S. Kuruvinashetti 《Euphytica》2006,149(1-2):113-120

Summary Fusarium wilt (Fusarium udum Butler) is a soil borne disease of pigeonpea which causes substantial yield losses. The disease can occur at any stage of plant development, from the young seedling to the pod filling stage. Though resistance is simply inherited, transfer to locally adapted cultivars has been difficult due to linkage drag and difficulty in accurate phenotyping, except in sick plots. An attempt was made to identify RAPD markers associated with wilt phenotype by using F2 populations derived from contrasting parents; GSl (susceptible) ‘ICPL87119 (resistant) and GS1’ ICP8863 (resistant). Parents and F₂s were grown in a national _Fusarium sick-plot at Gulbarga, India and phenotyped as resistant or susceptible during the entire crop growth period. In both the crosses, resistance to wilt segregated as a monogenic dominant character. DNA samples extracted from sick plot grown, early seedling stage plants of parents and 254 F₂ plants of GS1 × ICPL87119 were held separately for marker identification. PCR reactions using 340 random decamer primers with genomic DNA of parents resulted in detection of 45 polymorphic amplicons from 39 primers. PCR testing of bulked DNA from subsets of resistant and susceptible plants revealed the presence of two amplicons at 704 bp and 500 bp (OPM03704 and OPAC11500) with susceptibility. Analysis of individual F₂ plants showed a segregation ratio of 3: 1 for the presence: absence of the amplicon in both crosses. Considering the wilt reaction and susceptibility-linked RAPD marker, it was possible to deduce genotype of every F₂ plant and the genotypic ratio for wilt reaction was 1RR: 2Rr: 1rr, as expected.  相似文献   

Association of polymorphism in the prolactin promoter and egg quality traits in laying hens     

Bhattacharya TK  Chatterjee RN  Sharma RP  Rajkumar U  Niranjan M  Reddy BL 《British poultry science》2011,52(5):551-557

1. Single strand conformation polymorphism analysis and DNA sequencing was performed in White Leghorn hens to explore the polymorphisms present in the promoter of the prolactin gene. The effects of different genotypes on egg production and quality traits were determined, and expression of the prolactin gene in different genotypes was quantified by real time-PCR.

2. Five genotypes and four alleles at each of two Fragments of the promoter were found, of which the FG genotype in Fragment 1 and the PQ genotype in Fragment 2 were the most predominant genotypes.

3. The genotypes of Fragment 1 had significant effects (P?

4. Prolactin expression in the genotypes of Fragment 1 differed significantly and GH genotyped birds had the highest level of expression. The genotypes of Fragment 2 did not show any significant differences of expression.

5. It was concluded that the prolactin gene promoter was highly polymorphic, and had significant effects on egg quality traits in White Leghorn hens.  相似文献   

Genome organization in coffee as revealed by EST PCRRFLP,SNPs and SSR analysis     

Manoj Kumar Mishra  Patrizia Tornincasa  Barbara De Nardi  Elisa Asquini  René Dreos  Lorenzo Del Terra  Rajkumar Rathinavelu  Paola Rovelli  Alberto Pallavicini  Giorgio Graziosi 《Journal of Crop Science and Biotechnology》2011,14(1):25-37

An EST-based PCR-RFLP method was employed to gain insight into genome organization in eight allopolyploid Coffea arabica cultivars and seven diploid coffee species. The PCR-amplified products at 19 EST loci were digested with 46 different restriction enzymes and size fractioned in agarose gels. Most often, the sum of the fragments length was double or more than the PCR product. In arabica, this condition could be explained by assuming the presence of duplicated loci in paralogous chromosomes and this was supported by considerable evidence of multiple loci SSR amplification. Based on the RFLP analysis, 12 EST loci were polymorphic. The level of polymorphism was higher in different species compared to the arabica varieties. Sequencing of the amplified products revealed a SNP frequency of 0.021 among diploid species and of 0.007 among arabica varieties. We propose that the involvement of two genomes in C. arabica maintains a residual level of heterozygosity in the form of paralogous chromosomes, while the self-fertilization in this species tends to drive of homozygosity. The heterozygosity of paralogous chromosomes in arabica creates valuable polymorphism essential for species diversity and survival in various ecological niches, while self-fertility tends to preserve in homozygosity many genes of functional significance.  相似文献   

Response of upland cotton (<Emphasis Type="Italic">G.hirsutum</Emphasis> L.) genotypes to drought stress using drought tolerance indices     

Chandrakant?SinghEmail author  Vijay?Kumar  Indivar?Prasad  Vishal?R.?Patil  B.?K.?Rajkumar 《Journal of Crop Science and Biotechnology》2016,19(1):53-59

Drought tolerance as such is often not considered to be an independent trait by plant breeders. The objective of this study was to evaluate eight drought tolerance indices, namely stress susceptibility index (SSI), yield stability index (YSI), yield reduction ratio (Yr), yield index (YI), tolerance index (TOL), mean productivity (MP), geometric mean productivity (GMP), and stress tolerance index (STI) in upland cotton (G. hirsutum L.) genotypes. For this purpose, 16 genotypes were sampled during the 2013-2014 growing seasons under both normal and drought-stress field conditions at the Main Cotton Research Station of Navsari Agricultural University, Surat, India. The drought tolerance indices were calculated based on seed cotton yield under drought stress and non-stress conditions. Mean comparison of drought tolerance indices and seed cotton yield validated the significant influences of drought stress on yield as well as significant differences among genotypes. Results of calculated correlation coefficients and multivariate analyses showed that GMP, MP and STI indices were able to discriminate drought-sensitive and tolerant genotypes. Cluster analysis using the drought-tolerance indices divided the 16 genotypes into tolerant and susceptible groups. Two genotypes, G.Cot.16 × H-1353/10 and H-1353/10 × G.Cot.16 gave good yield response under drought conditions leading to their stability during water stress conditions. Based on multivariate analyses using the indices individually or in combinations, it was possible to identify the most yield-stable genotypes across the environments. Overall, we concluded that GMP, MP and STI indices can be efficiently exploited not only for screening drought tolerance but also to identify superior genotypessuitable for both stress and non-stress field conditions.  相似文献   

Molecular mapping of genomic regions harboring QTLs for stalk rot resistance in sorghum   总被引：1，自引：0，他引：1  

P. Srinivasa Reddy  B. Fakrudin  Rajkumar  S. M. Punnuri  S. S. Arun  M. S. Kuruvinashetti  I. K. Das  N. Seetharama 《Euphytica》2008,159(1-2):191-198

Stalk rot, also called as charcoal rot in India, caused by Macrophomina phaseolina, is an economically important, soil borne disease in major sorghum growing areas across the world. A population of F₉ generation recombinant inbred lines (RILs), derived from IS22380 (susceptible) × E36-1 (resistant), along with parents were phenotyped in sick plots at two locations (Dharwad and Bijapur, Karnataka, India). A total of 85 polymorphic marker loci (62 nuclear and 4 genic SSRs, 19 RAPDs) was available for the construction of genetic map, spanning 650.3 cM in all the ten linkage groups. Analysis with QTL Cartographer (2.5b), adopting composite interval mapping method (LOD > 2.0) at both locations, revealed 5 QTLs at Dharwad and 4 QTLs at Bijapur locations for the component traits of charcoal rot disease resistance. QTLs for number of internodes crossed, length of infection and per cent lodging accounted for 31.83, 10.76 and 18.90 per cent at Dharwad location and 14.87, 10.47 and 26.44 per cent phenotypic variability at Bijapur location, respectively. The QTLs for number of internodes crossed by the rot, length of infection and percent lodging were common across two locations. These QTLs, consistent over environments for the component traits, are likely to assist in marker-assisted selection (MAS) for charcoal rot resistance in sorghum.  相似文献   

Integrating marker assisted background analysis with foreground selection for identification of superior bacterial blight resistant recombinants in Basmati rice     

S. Gopalakrishnan    R. K. Sharma    K. Anand Rajkumar  M. Joseph    V. P. Singh    A. K. Singh    K. V. Bhat    N. K. Singh    T. Mohapatra 《Plant Breeding》2008,127(2):131-139

Basmati rice is highly susceptible to bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae. Transfer of BB resistance genes from non‐Basmati sources to Basmati through cross‐hybridization requires strict monitoring for recovery of the desirable Basmati quality traits in the recombinants, which show complex inheritance pattern. We integrated background analysis using mapped microsatellite markers with foreground selection to identify superior lines that combine useful genes from a non‐Basmati BB resistance donor line IRBB55 with grain and cooking quality characteristics of the popular Basmati rice variety ‘Pusa Basmati 1’ (PB 1) employing backcross pedigree strategy. Foreground selection using linked markers ensured presence of two genes, xa13 and Xa21 for BB resistance from IRBB55, and the recurrent parent PB 1 allele for the waxy locus giving intermediate amylose content and maintainer allele at fertility restorer locus in the BC₁F₅ recombinants. Background analysis enabled selection of recombinants with recurrent parent genome to the extent of 86.3% along with the quality traits. The extent of introgression of non‐Basmati donor chromosome segments in the superior selections was estimated to be < 7.8 Mb and < 6.7 Mb in the xa13 and Xa21 linked genomic regions, respectively. Association mapping identified three quantitative trait loci, one each for 1000‐grain weight, fertile grains/panicle and cooked kernel length. The backcross‐pedigree breeding strategy facilitated recovery of additional desirable characteristics from the donor in some of the selections. The elite selection Pusa 1460‐01‐32‐6‐7‐67 with maximum genomic background and quality characteristics of the recurrent Basmati parent gave resistance reaction against BB, similar to that of the non‐Basmati resistant check variety and recorded an yield advantage of 11.9% over the best check in the multiplication agronomic trial in the Basmati growing region of India. This line, which has been released as a new variety in the name of ‘Improved Pusa Basmati 1’ for commercial cultivation in India, is an example of successful application of marker assisted selection to variety development.  相似文献   

Studies on the occurrence of infectious myonecrosis virus in pond‐reared Litopenaeus vannamei (Boone, 1931) in India          下载免费PDF全文

A S Sahul Hameed  S Abdul Majeed  S Vimal  N Madan  T Rajkumar  S Santhoshkumar  S Sivakumar 《Journal of fish diseases》2017,40(12):1823-1830

Whiteleg shrimp, Litopenaeus vannamei, with clinical sign of muscle opaqueness with reddish colour at the distal abdominal segments were observed in farms located in West Bengal State, India. The mortality of shrimp in all disease outbreak ponds ranged from 20% to 50%, and mortality increased gradually. The RT‐PCR assay of these samples using primer sets specific to infectious myonecrosis virus (IMNV) revealed its presence in the disease outbreak ponds. The IMNV infection was reproduced in healthy shrimp by intramuscular injection to satisfy River's postulates. The virus caused mortality in intramuscularly challenged shrimp, but failed to cause mortality by oral route. Tissue distribution of IMNV in infected shrimp by RT‐PCR assay revealed the presence of this virus in haemolymph, gill, hepatopancreas and muscle. This study confirms that the disease outbreak which occurred in the shrimp farms located at Purba Medinipur District, West Bengal, India, was due to IMNV.  相似文献   

Mud crab,Scylla tranquebarica (Decapoda: Portunidae), a new host for the white spot syndrome virus     

Ayyaru Gopalakrishnan  Mayalagu Rajkumar  Jun Sun  Min Wang  Kesavanandha Senthil Kumar 《Aquaculture Research》2011,42(2):308-312

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