DNA marker characterization for allele mining of blast and bacterial leaf blight resistant genes and evaluation for grain yield

Landraces of rice were evaluated for blast and bacterial leaf blight (BLB) resistance, via tightly linked SSR markers and by phenotyping for flowering time, maturity and grain yield. Correlation between flowering maturity and grain yield was carried out using 162 local landraces and traditional rice cultivars. Days for 50% flowering ranged from 59 to 157 days, maturity from 93 to 192 days and seed yield per plant ranged from 0.24 to 33.3 g. Strong association was observed between flowering time and maturity time. Marker RG64 linked to Pi-2, a major dominant blast resistance gene on Chromosome 6 and marker pTA248 on Chromosome 11 linked to Xa21, a resistant gene to bacterial leaf blight were used to detect the presence of resistant alleles. Three different types of bands of 1 kb carrying Xa21 resistant allele and two susceptible alleles of 700 and 750 bp were amplified using pTA248. 14 rice genotypes were resistant for BLB, 46 genotypes showed susceptible banding pattern, and 87 genotypes were in heterozygous condition for resistance. 28 genotypes carried resistant alleles for both blast and bacterial leaf from among them Gowri Sanna, Ponni, Antharsali and Doddabyranellu were popularly preferred by the farmers. These can serve as donor lines for transferring of both resistances simultaneously.Keywords: Landraces, blast, bacterial leaf blight, grain yield, DNA markersAfrican Journal of Biotechnology Vol. 12(18), pp. 2331-234

Detection of epistasis through triple test cross (TTC) analysis in maize (Zea mays L.)

The present study was carried out to detect the epistasis present in two cross of maize through triple test cross (TTC) analysis. The mean squares due to total epistasis was highly significant at P?0.01 for all the characters in both C-I and C-II, except for ear length in C-I. The i type of epistasis was highly significant for the traits such as days totasseling, days to silking, earlength, ear circumference, kernels row-1,100 grain weight and shelling percentage in C-I and in C-II, ‘i’ type was non-significant for ASI, ear length, kernels row-1and grain yield plot-1. Both j type and l type of epistasis were significant for all characters in both C-I and C-II, except for ear length in C-I and days to silking in C-II. The estimate of additive genetic component (D) was highly significant for all characters in both C-I and C-II. Epistasis played a significant role in the inheritance of all the characters in both C-I and C-II except for ear length in C-I. Both additive and dominance components of genetic variance with a predominance of dominance genetic variance played an important role in the inheritance of all the quantitative traits except ear length in C-I and kernel rows ear-1 in C-II

De novo genome assembly and annotation of rice sheath rot fungus Sarocladium oryzae reveals genes involved in Helvolic acid and Cerulenin biosynthesis pathways

Morphology of Saro-13 isolate used for whole genome sequencing. (PDF 13621 kb

DNA marker-assisted evaluation of cultivated and local mulberry genotypes of southern India

Germplasm evaluation is essential in any crop improvement program and genetic characterization atmorphological and molecular level is very vital for breeding programs to be successful. Twenty six cultivated and localgenotypes of mulberry were subjected to diversity analysis with RAPD markers. Among the total 31 RAPD primers studied, 24were polymorphic and 7 were monomorphic. Of the total 197 loci obtained from 24 polymorphic primers, 110 loci (55.83%)were polymorphic and 87 (44.16%) were monomorphic. A clear grouping was seen among the cultivated genotypes based onyield with varieties like S36, V1, S54 and M5 showing proximity to each other and sharing a close similarity. Local genotypesare rich reservoirs of resistant gene sources and are well acclimatized to the prevailing environmental conditions.Utilizationof these along with other high yielding varieties will produce various combinations of resistance sources which can beincorporated into high yielding varieties

Relationship between morphological and amplified fragment length polymorphism (AFLP) marker based genetic distance with heterosis in hot pepper (Capsicum annuum L.)

Identification of potential parents that produce the hybrids with superior yield is the most important step in developing hybrids to save the substantial resources. The present study was carried out to assess the morphological and amplified fragment length polymorphism (AFLP) marker based genetic diversity, to estimate mid parent heterosis and to correlate the estimated parental genetic diversity with heterosis chilli. Five CMS B - lines and 30 testers were used for morphological and AFLP marker genetic divergence analysis. 150 hybrids were synthesized through Line × Tester (5 × 30) mating design and were used to estimate the mid-parent heterosis for nine characters at two locations. 35 parents were examined for nine morphological traits and were grouped in to six clusters. These parents were also examined for eight AFLP primers combinations and were grouped into seven clusters. More than 50% of hybrids showed significant mid-parent heterosis for both green and red fruit yield plant-1. Hence, there is a much potential for development of good yielding hybrids. The positive significant correlation was found between morphological and AFLP marker distance of the parents with heterosis for plant height (r = 0.17 and 0.38), green fruit yield plant-1 (r = 0.19 and 0.25) and red fruit yield plant-1 (r = 0.20 and 0.34); however, the correlation coefficients were not strong in these traits. Genetic distance between parents was not strong enough to predict the performance of the hybrids and proved to be of no predictive value.Keywords: Correlation, molecular markers, genetic diversity, chill

Indica rice genome assembly, annotation and mining of blast disease resistance genes

Sequence data size for rice cultivars. (XLSX 15 kb

Correlation study for Protein Content, Grain yield and Yield Contributing Traits in Quality Protein Maize (QPM) (Zea mays L.)

Seventy Quality Protein Maize (QPM) (Zea mays L.) hybrids were grown in duplicate randomized complete block design forcharacter association study to assess the relationship among total grain protein content, grain yield and its components. Totalgrain protein showed significant correlation with plant height and ear height. Character association analysis revealed strongpositive association of Grain yield per plant with plant height, ear height, ear length, ear diameter, kernel rows per cob, kernelsper row, test weight and shelling per cent. Total grain protein showed strong negative association with days to 50 % flowering,days to anthesis and days to 50% silking. Hence, simultaneous selection of plant height and ear height would contribute for theimprovement of the grain yield per plant and total protein content in the grains at the same time