Browsing by Author "SRAVANI, DINASARAPU"
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ThesisItem Open Access GENETIC CHARACTERIZATION AND MOLECULAR STUDIES ON PROTEIN CONTENT USING MICROSATELLITES IN RICE (Oryza sativa L.)(PROFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY, RAJENDRANAGAR, HYDERABAD, 2015) SRAVANI, DINASARAPU; DAYAKAR REDDY, TThe present investigation was undertaken in rice to elicit information on combining ability, heterosis, character association, direct and indirect effects, stability of hybrids for protein content, yield, yield components and quality characters of hybrids at different locations of Telangana state and also to map the gene(s) for protein content using microsatellite markers Eight divergent parents were selected and crossed in diallel fashion excluding reciprocals during kharif, 2012 at DRR Farm, Directorate of Rice Research, Hyderabad, Telangana state. During rabi, 2012-13 the 28 cross combinations along with their parents were evaluated at three different locations viz., Jagitial, Warangal, and Hyderabad for protein content, yield, yield components and quality characters. The analysis of variance of 36 genotypes (eight parents and twenty-eight cross combinations) revealed significant differences among the parents and hybrids evaluated at different locations for all the characters under study. The combining ability analysis of variance in pooled analysis, showed significant differences due to locations, parents, hybrids and various interactions indicating the existence of sufficient variation in the material under study. The gca and sca variances indicated that non additive gene action was predominant in the expression of protein content, yield, yield component traits and quality characters In pooled analysis, none of the parents was found to exhibit significant gca effects for all the characters studied. Jalanidhi , Phalguna were found to be promising general combiners for protein, grain yield per plant and other traits. Based on significant sca effects, in pooled analysis, for protein content, seven crosses recorded significant positive sca effects. On the whole, twelve cross combinations viz., Suraksha × Jalanidhi, Suraksha × MTU1010, Suraksha × Swarna, Jalanidhi × Phalguna, Jalanidhi × Mahamaya, Jalanidhi × MTU1010, Phalguna × RPBIO226, Phalguna × Swarna, Mahamaya × RPBIO226, MTU1010 × BPT5204, RPBIO 226 × BPT5204, RPBIO 226 × Swarna have been identified as promising based on per se performance, sca effects and heterosis for yield and its attributes in pooled analysis. Besides yield these cross combinations also possessed desirable quality characters like milling per cent, head rice recovery per cent, water uptake, Alkali Spreading Value. But in case of protein content, none of the cross combination showed significant heterosis in desirable direction though Mahamaya × Swarna, Phalguna × Swarna, Suraksha× Mahamaya, Jalanidhi × MTU1010, Suraksha × Jalanidhi, Phalguna × RPBIO226 had high Protein content among all cross combinations with optimum yield. Genotype x environment interaction studies with twenty eight hybrids at different locations for protein content, yield and yield attributing traits by Eberhart and Russell revealed four hybrids viz., Suraksha × Jalanidhi , Jalanidhi × MTU1010, Phalguna × Swarna , BPT 5204 × Swarna were identified as stable hybrids for protein content,while in case of grain yield per plant the hybrids Jalanidhi × Mahamaya, MTU1010× BPT5204 was considered as stable cross combination. The character association studies revealed that the attributes viz. number of productive tillers per plant, plant height, kernel breadth and kernel length had a significant positive association along with direct effect on grain yield per plant suggesting selection of these traits will be useful for the improvement of grain yield and grain yield per plant had a negative significant association with protein content in pooled analysis. Based on the present study, it can be emphasized that Jalanidhi × Mahamaya, MTU1010 × BPT 5204 are stable with the desirable sca effects, heterosis and per se performance for grain yield and other important attributes. Suraksha × Jalanidhi and Phalguna × Swarna had high protein content among all cross combinations with optimum yield. These hybrids may be further tested over locations, seasons and years and recommended for commercial release. For mapping of gene(s) for protein content, RM1369, RM263 and RM337 were identified to be associated with protein content. RM337 showed highest significant variation with protein at the tune of recombination frequency 0.23. So further investigation is warranted to identify closely linked markers by increasing the population size and number of microsatellite markers.ThesisItem Open Access MAPPING OF GENE(S) FOR RESISTANCE TO POWDERY MILDEW IN SESAMUM (Sesamum indicum L.)(ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY, 2011) SRAVANI, DINASARAPU; ANURADHA, GPowdery mildew is a serious disease of sesamum (Sesamum indicum L). It occurs in epidemics under heavy rainfall conditions followed by low night temperatures and high humid conditions. Powdery mildew causes yield loss of 25 to 50% depending upon the severity. Classical breeding for incorporation of resistance using backcrossing is difficult because consistent disease reaction in the field is hard to achieve due to environmental factors. Identification of molecular markers linked to powdery mildew resistant gene(s) is one approach to improve selection for resistant cultivars. The objective of this study was to identify the mode of inheritance of disease resistance and to use microsatellite (SSR) markers to identify markers linked to resistance gene(s) and map gene(s) resistance to powdery mildew. In the present study Swetha til, a high yielding popular white seeded variety but susceptible to powdery mildew and BB3-8 accession of Sesamum mulayanum resistant to powdery mildew from RARS, Jagtial were selected as parents for hybridization. F1 was developed by crossing the resistant parent ( BB3-8 accession of Sesamum mulayanum ) and the susceptible parent (Swetha til) during Late summer, 2009. F1 was selfed during Kharif 2010 to generate F2. Four populations including P1, P2 , F1, F2 were sown during Late summer, 2010 to screen powdery mildew under field conditions. The F1 of the cross between Swetha til and BB3-8 accession of S.mulayanum exhibited susceptible reaction to the disease suggesting resistance to be governed by recessive gene. On screening of 104 plants of F2 population, the plants segregated into 61 susceptible and 43 resistant plants. Chi-square analysis showed the observed ratio to confirm the expected ratio of 9:7 ratio (susceptible : resistant) and the resistance to disease was governed by two pairs of recessive genes contributed by S.mulayanum. The two parents were screened for parental polymorphism using 300 sesame microsatellite markers, of which 240 showed clear amplification pattern and 24 markers exhibited polymorphism (10%) and the same were used for genotyping. DNA from 104 F2 progenies were collected for genotyping with 24 Polymorphic SSR primers. Molecular linkage map was constructed with SSR markers SM10 178 and SM10 176 using the MAPMAKER/EXP version 3.0 Both the markers were mapped to one and the same linkage group at a distance of 14.2 cM. These two markers were found to be linked to the powdery mildew resistance gene.