Protoplast fusions are important tools in strain improvement for bringing genetic recombination and developing hybrid strains in filamentous fungi. These are the powerful techniques for engineering of microbial strains with desirable different properties. The molecular characterization of two parent's strains (Trichoderma harzianum NBAII Th 1, Trichoderma viride NBAII Tv 23) and their corresponding fusants, produced by protoplast fusion, was investigated by random amplified polymorphic DNA (RAPD), ISSR (inter-simple sequence repeats) and internal transcribed spacer (ITS) markers. Specific results for fingerprinting were obtained by the 20 primers of each RAPD and ISSR, and four primers of ITS, respectively. These markers produced different fragment patterns with varied number of bands and yielded a total of 419 distinct bands. 13.3% were considered as polymorphic bands and 86.7% were considered as monomorphic bands. For RAPD marker, the OPC-04 primer has showed the highest polymorphism, 58.3%. While in ISSR marker, the UBC-835 primer has showed the highest polymorphism, 57.2%. The dendrogram based on RAPD marker results grouped the two parent's strains and 21 fusants into two different clusters with about 97% genetic similarity. While the dendrogram based on ISSR and ITS markers results grouped the two parent's strains and 21 fusants into two different clusters with about 88% genetic similarity. Moreover, the smallest genetic distance (0.01) was estimated between fusant-10 and fusant-12; moreover, fusant-8 and fusant-20 relatively have the highest genetic distance. Our results are consistent with the conclusion that understanding the genetic variation within parent Trichoderma strains and their corresponding fusants and molecular occurrence of protoplast fusion using RAPD, ISSR and ITS markers.

J o u rn al of M ic ro b ia l & Bioc h e m ic a l Te chno lo g y

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The present research was conducted to study earliness and their correlations with grain yield in rice breeding. It was carried out during 2012 and 2017 growing seasons at RRTC Farm, Sakha, Kafr El-Sheikh, Egypt. F 1 were evaluated along with their parents for genotypic variation. ANOVA revealed significant differences at the 0.01 level among crosses and parents as well as between parents and crosses. These results indicated a wide range of variations among parental groups. The mean squares of parents vs. crosses were found to be significant for all grain yield and its component characters. Variance among crosses indicated significant SCA effects at the 0.01 level for all its component traits. Concerning GCA effects four entries; Sakha 101, Novator, Anait and Large Stigma exhibited positive significant estimates at 0.01 levels for grain yield /plant. The desirable hybrid combinations Giza 179 X Large Stigma and Sakha 105 X VNIRB 572 exhibited significant values of SCA effects at 0.01 and 0.05 levels for grain yield. Heritability estimates in narrow sense ranged from low to moderate. Sakha 101 X Novator, Sakha 106 X Novator and Giza 179 X Large Stigma were the promising hybrid combinations for improving yield character according to results for mid and better parent heterosis. Positive significant correlation coefficient at 0.01 level was recorded between 1000-grain weight and grain yield/plant. All of 11 SSR motifs were polymorphic and produced varying number of alleles with different size ranges. A total of 99 alleles were identified with 10 varieties under study.