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Gowda V.,Central Sericultural Germplasm Resources Center | Ashwath S.K.,Central Silkworm Central Sericultural Research and Training Institute | Kalpana G.V.,P4 Basic Seed Farm
Indian Journal of Sericulture | Year: 2012

In the present study, with the main aim of identifying the promising four-way cross bivoltine hybrid combinations with superior quantitative and qualitative traits, an attempt has been made to assess and evaluate newly developed four-way cross hybrids of bivoltine silkworm Bombyx mori L. Using oval and dumb-bell bivoltine foundation crosses, a total of 45 four-way cross hybrids were prepared, reared and assessed through multiple trait evaluation index (E.I.) along with the control (CSR2xCSR27) x (CSR6xCSR26). The data showed that21 double hybrids have mean E. I. values > 50, which were significantly higher when compared to the control, where the mean E.I. value was found to be only 44.15. The highest E.I. value of 56.11 was recorded in the four-way cross (CSR2 x JPN8) x (D13xSl) closely followed by 55.14 in (CSR2xCSR12) x (CSROxSl) and 54.61 in (CSR2xJPN8) x (CSR26xSl). Results of the present investigation have shown the prospects of identifying promising four-way cross bivoltine hybrids for commercil exploitation. Source


Krishnan R.R.,Central Sericultural Research and Training Institute | Naik V.G.,Central Sericultural Research and Training Institute | Ramesh S.R.,Central Sericultural Germplasm Resources Center | Qadri S.M.H.,Central Sericultural Research and Training Institute
Plant Genetic Resources: Characterisation and Utilisation | Year: 2014

The secret art of silk culture along with mulberry seeds is presumed to have spread from China to other parts of the world including India through the famous Silk Road. In this study, we investigated a set of 36 important mulberry genotypes (designated as 'breeders' collection') of historical importance that have been frequently used in Indian crop improvement programmes over the last five decades. This study is the first to employ a large number of microsatellite markers (140 screened; 70 used for profiling) to elucidate the diversity, structure and breeding history of mulberry. The cluster and STRUCTURE analysis corroborated with the known genetic relationships and origin. The groupings by STRUCTURE (k= 4) confirm parallel breeding efforts undertaken in the eastern, southern and northern regions of the country. The cultivar 'Mysore Local' shares a common parent with 'Berhampore Local', and this supports the historical records of its introduction from eastern India to the Kingdom of Mysore by the erstwhile ruler Tippu Sultan. The popular variety 'Kanva-2' shared a common male parent with the Japanese variety 'Kousen', supporting the contribution of exotic progenitors in Indian cultivars. The findings of this study will be useful in formulating new strategies for mulberry improvement and reveals the historical events of the introduction and spread of cultivated mulberry in the Indian subcontinent. © 2013 NIAB. Source


Krishnan R.R.,Central Sericultural Research and Training Institute | Sumathy R.,Central Sericultural Research and Training Institute | Ramesh S.R.,Central Sericultural Germplasm Resources Center | Bindroo B.B.,Central Sericultural Research and Training Institute | Naik G.V.,Central Sericultural Research and Training Institute
Crop Science | Year: 2014

Sampling core collections containing a diverse set of entries has been practiced over the last two decades for a number of crops and has become a vital component of modern day crop improvement programs. A diverse, multipurpose core collection should represent the maximum genetic diversity available in an entire germplasm collection with a small number of entries. Selection of genetically distant entries that represent the maximum diversity of the entire germplasm collection is a challenging task that has been improved over the years. In this study, we introduce the similarity elimination (SimEli) method to sample genetically distant entries for the development of core collections, which was used to sample a diverse core collection of mulberry accessions using phenotypic markers. The performance of the SimEli method was compared with that of the PowerCore algorithm for phenotypic markers and with that of the Core Hunter and genetic distance optimization (GDOpt) algorithms for simple sequence repeat (SSR) markers. The SimEli method effectively selected genetically distant entries, whereas PowerCore proved efficient for selecting outliers among a small number of entries. However, the SimEli method outperformed the Core Hunter algorithm in selecting distant entries with high mean and minimum entry to nearest entry distance values. The Core Hunter collections retained a greater number of alleles than did collections developed using the SimEli method only when increased weight was given to Shannon's diversity index when using Core Hunter. The SimEli method is more user-friendly, involves simple steps, and requires less computational time than other leading programs for the development of core collections. © Crop Science Society of America. Source


Gowda V.,Central Sericultural Germplasm Resources Center | Ashwath S.K.,Central Sericultural Research and Training Institute | Kalpana G.V.,P4 Basic Seed Farm | Rekha M.,Central Sericultural Research and Training Institute | Bindroo B.B.,Central Sericultural Research and Training Institute
Indian Journal of Sericulture | Year: 2014

Genotype-environment (G-E) interaction and stability parameters were analyzed for ten each of oval and dumb bell silkworm bivoltine breeds reared during three different seasons of the year. Quantitative economic traits viz., fecundity, cocoon yield /10000 larvae by number, cocoon yield /10000 larvae by weight, single cocoon weight, single shell weight, cocoon shell percentage, filament length, denier, raw silk percentage, renditta, neatness and boil-off loss were evaluated. The mean sum of squares (MS) for the breeds and environments was highly significant (p < 0.01) in both oval and dumbbell breeds in respect of all the traits except for renditta clearly indicating substantial variation among the breeds and seasons. However, the Genotype Environment interaction was found to be nonsignificant for all the traits among oval breeds, while among the dumbbells, only four traits, namely, cocoon yield /10000 larvae by number, cocoon yield/10000 larvae by weight, filament length and neatness showed significant G E interaction. Two stability parameters, viz., regression coefficient (bi) and deviation from regression (s2di) were analyzed in both oval and dumbbell breeds, which showed significant differences for most of the traits. Based on the values of the two stability parameters for the 12 economic traits and cumulative ranking, CSR2, JPN8 among oval breeds and CSR16 among dumbbell breeds were found to be stable breeds in the expression of quantitative traits irrespective of the seasons, while, S5 (oval) and BBE267 (dumb-bell) expressed less stability. Source


Rao Ananda A.,Central Sericultural Germplasm Resources Center | Vijayan K.,RCS | Krubakaran M.,Central Sericultural Germplasm Resources Center | Borpujari M.M.,Central Sericultural Germplasm Resources Center | Kamble C.K.,Central Sericultural Germplasm Resources Center
Journal of Horticultural Science and Biotechnology | Year: 2011

Nine isozyme patterns were studied to deduce the level of genetic diversity and inter-relationships among 14 species of mulberry (Morus spp. L) used in breeding programmes. -Esterase (EST), peroxidase (PoX), diaphorase (DIA), and polyphenol oxidase (PPO) produced 12 isozyme loci and a total of 22 alleles.The percentage of polymorphic loci and the average number of alleles per locus ranged from 50 - 75% and 1.336 - 1.667 respectively. Among 80 wild accessions of two wild and two domesticated species of Morus, 22 accessions of M. alba exhibited a higher number of polymorphic loci (75%), a higher polymorphic index (0.398), average number of alleles per locus (1.457), and expected heterozygosity (0.339) compared to the three other Morus species under study. Evidence for a higher rate of gene flow was found between populations of M. alba and M. indica compared to that between the other three species sampled. Phylogenetic clustering of the 80 wild mulberry accessions indicated three major groups. Accessions of the domesticated species grouped into one cluster, while accessions of the wild species grouped into one major and one minor cluster. Among all the isozyme loci, EST-2 was present only in polyploid species. The resolving power of isozymes was less than that of molecular markers, hence molecular markers should be used for phylogenetic studies in mulberry. Source

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