Chander Parkash

In vitro maintenance of CMS lines of Indian cauliflower: an alternative for conventional CMS-based hybrid seed production

Summary Three Ogura cytoplasmic male-sterile (CMS lines) of Indian cauliflower (Brassica oleracea var. botrytis L.; Ogu1A, Ogu2A and Ogu3A) were compared for their in vitro regeneration ability using two types of explant, hypocotyls and curds (i.e., pre-floral fleshy apical meristems). The highest rate of in vitro establishment and the highest multiplication index were recorded in Ogu3A. Ogu2A showed poor in vitro establishment. The choice of explant had a significant impact on the morphogenetic potential of all three lines. Among the two types of explant, curds proved to be more efficient for the initial establishment of cultures.The highest rate of in vitro establishment and multiplication index were recorded for Ogu3A on Murashige and Skoog (MS) medium supplemented with 2.5 mg l-1 kinetin, 0.2 mg l-1 _- naphthaleneacetic acid and 0.2 mg l-1 gibberellic acid. The three CMS lines also showed significant variations in the numbers of roots induced per shoot.The maximum number of primary roots per shoot was recorded in Ogu3A on 0.5_ MS medium supplemented with 1.0 mg l-1 indole-3-butyric acid. In vitro-raised plants were hardened and used successfully for F1 hybrid development.When the F1 hybrids developed using in vitro-maintained or conventionally maintained CMS lines were compared, it was observed that variations in plant height, days to 50% curd maturity (DCM), and net curd fresh weight (FW) were lower in those F1 hybrids developed through in vitro-maintained CMS lines. In F1 hybrids developed from in vitro-raised CMS lines, the range of standard deviation (SD) values as percentages of the mean value for DCM and net curd FW were 2.5 - 3.7% and 6.6 - 10.7%, respectively. In contrast, the corresponding SD values ranged from 5.8 - 7.9% and from 13.6 - 19.9% for F1 hybrids developed from conventionally maintained CMS lines.This in vitro protocol, using curd explants, will be useful for the rapid multiplication of breeding lines of cauliflower without inbreeding depression, and for high-quality hybrid seed production.

Heterotic potential, potence ratio, combining ability and genetic control of yield and its contributing traits in cucumber (Cucumis sativus L.)

ABSTRACT The present investigation was undertaken in F1 population of 48 crosses, developed by crossing 16 lines (8 gynoecious) and 3 testers during the year 2011. All the parental lines and their F1 hybrids were evaluated in randomised complete block design for yield and its contributing traits during the year 2012. Experimental results revealed that parental lines LC-1-1, CGN-20953, CGN-19533, Gyne-5, LC-15-5 and testers Japanese Long Green and K-75 were found superior on the basis of mean performance and general combining ability effects. The cross combinations LC-1-1 × K-75 (monoecious), CGN-19533 × K-75 (gynoecious), CGN-20953 × Poinsette (gynoecious), Gyne-5 × K-75 (gynoecious) and LC-3-3 × Poinsette (monoecious) excelled based on per se performance, specific combining ability and heterosis studies. Further, performance of top 10 heterotic hybrids illustrated the presence over dominance effects in all the crosses except in one cross, where no dominance was observed. Gene action studies indicated that non-additive gene action governed all the traits under study, suggesting the importance of heterosis breeding for the development of high yielding stable parthenocarpic gynoecious hybrids in cucumber.

Genetic analysis of important antioxidant compounds in cabbage (Brassiaca oleracea var. capitata L.)

ABSTRACT The paucity of research on development of antioxidant-rich hybrids in cabbage by utilizing combining ability estimates, gene action, and heterosis motivated us to undertake this study. We made 60 crosses between 5 cytoplasmic male-sterile lines and 12 male-fertile testers during the summer of 2015, as per the line × tester design. The seedlings of all the parents and 60 F1 crosses, along with three checks, were transplanted during the Rabi (winter) season of 2015–2016 and evaluated using a randomized complete-block design. Combining ability, gene action, and heterosis were determined for different antioxidant compounds. Experimental results revealed that the range of cupric ion reducing antioxidant capacity (CUPRAC) [parents = 1.26–7.33 and hybrids = 0.04–6.54 μmol trolox/g], ferric reducing ability of plasma (FRAP) [parents = 1.65–4.76 and hybrids = 0.16–4.67 μmol trolox/g], β-carotene (parents = 0.44–2.29 and hybrids = 0.04–1.89 μg/100 g), and chlorophyll-a (parents = 0.71–4.08 and hybrids = 0.19–3.08 mg/g f.w.) for hybrids was lower than that of the parents because of outbreeding depression. The parental lines 6A, 208A, 83-5-8, and Sel-5-83-6 were found to be good general combiners for most of the antioxidant compounds studied. Based on the mean performance, specific combining ability effects and heterosis, five hybrid combinations viz., 9A × KIRC-8 for CUPRAC and FRAP; 208A × C-122 for ascorbic acid; 6A × Chhaki-2 for total carotenoids and β-carotene; 831A × Chhaki-2 for chlorophyll-a; and 6A × 83-5-8 for chlorophyll-b and total chlorophyll content, were most promising. The ratio of general combining ability (GCA) and specific combining ability (SCA) variances, i.e., [2 σ2g/(2σ2g + σ2s)], which reflects the relative importance of GCA versus SCA, was less than unity for different antioxidant compounds, which implied that for these traits, nonadditive gene effects were more important than additive effects. The numerical values of range for contribution of lines × testers interaction for different traits (41.47–70.18%) were found to be higher than the individual contribution of lines (11.24–47.22%) and testers (8.31–21.76%). Hence, heterosis could be exploited for developing antioxidant-rich hybrid cabbage.

Genetic divergence and interaction among CUPRAC, FRAP and total phenolics content in cauliflower (Brassica oleracea var. botrytis L.)

Antioxidant capacity and total phenolics content were estimated in 46 cauliflower lines to determine genetic variability, heritability and correlation among them with the objective to formulate breeding strategies for development cultivars with higher antioxidant capacity. The genotypes comprised of six CMS lines, few advance breeding lines and other core collection of our institute. Significant variability was recorded for CUPRAC, FRAP and total phenolics content indicating the scope for improvement in these traits based on various breeding strategies. Phenotypic co-efficient of variation (PCV) was higher (43.01, 73.07 and 64.28) than genotypic co-efficient of variation (GCV) (41.34, 71.83 and 63.88) in all cases indicating the role of environment in expression of these traits. However improvement for these traits is possible through selection and heterosis breeding as broad sense heritability (92.44% to 98.75%) and genetic advance as percentage of mean (82.46% to 130.87%) was high for all the traits. Correlation coefficient analysis revealed that CUPRAC, FRAP and total phenolics had significant positive correlation among each other. However, none of them had any significant correlation with marketable yield. Fourty six genotypes were classified into 6 groups based on non-hierarchical cluster analysis and phenotypic divergence. This study will pave the way for breeding of cauliflower cultivars and hybrids with higher antioxidant capacity and phenolics content.

Biodiversity in Lilium : A Review

Lilium is a subbstantial genus administered throughout temperate and cooler regions of the Northern Hemisphere consisting approximately 110 species. The genus possess a great genetic diversity in many valuable horticultural traits which is manifested in flower colour, forms, shape, size, fragrance, resistance to diseases, and many physiological characteristics. Intensive agricultural practices, climate change and industrialization are having a straight impact on biodiversity. Comprehensive understanding of the species, including levels and form of genetic variation forms the basis for the successful management and safeguarding of populations of rare, endangered or threatened species. The biodiversity become important components of different ecosystems. Use of single new improved varieties of crops for large areas is a big threat for crop biodiversity. This review concentrates to provide species-level information on biodiversity in the genus lilium and their future use in breeding programs. We focus mainly on species used in breeding programme and grown mainly for cut flowers and pot production. For example; trumpet shaped Lilium species showed comparative better prospective for exploitation than other species. We also present a brief summary on research area that needs further development using biotechnological techniques like molecular assisted breeding, QTLs and GISH/FISH and chloroplast genomes for comparative and phylogenetic analyses.

‘Ogura’-based ‘CMS’ lines with different nuclear backgrounds of cabbage revealed substantial diversity at morphological and molecular levels

A comprehensive study on characterization and genetic diversity analysis was carried out in 16 ‘Ogura’-based ‘CMS’ lines of cabbage using 14 agro-morphological traits and 29 SSR markers. Agro-morphological characterization depicted considerable variations for different horticultural traits studied. The genotype, ZHA-2, performed better for most of the economically important quantitative traits. Further, gross head weight (0.76), head length (0.60) and head width (0.83) revealed significant positive correlation with net head weight. Dendrogram based on 10 quantitative traits exhibited considerable diversity among different CMS lines and principle component analysis (PCA) indicated that net and gross head weight, and head length and width are the main components of divergence between 16 CMS lines of cabbage. In molecular study, a total of 58 alleles were amplified by 29 SSR primers, averaging to 2.0 alleles in each locus. High mean values of Shannon’s Information index (0.62), expected (0.45) and observed (0.32) heterozygosity and polymorphic information content (0.35) depicted substantial polymorphism. Dendrogram based on Jaccard’s similarity coefficient constructed two major groups and eight sub-groups, which revealed substantial diversity among different CMS lines. In overall, based on agro-morphological and molecular studies genotype RRMA, ZHA-2 and RCA were found most divergent. Hence, they have immense potential in future breeding programs for the high-yielding hybrid development in cabbage.

Heterosis and combining ability analysis in snowball cauliflower using indigenously developed CMS lines

Five CMS lines, Ogu12A, Ogu13A, Ogu14A, Ogu15A and Ogu16A were selected among fifteen lines after BC7 based on superior commercial, floral and seed setting traits. Line × Tester analysis was done by taking these five CMS lines as female parent with ten diverse lines of snowball cauliflower as testers. Data were recorded for 14 important vegetative and commercial traits. For days to 50% curd initiation and days to 50% curd maturity the CMS line Ogu15A exhibited significantly high GCA effect in negative direction (−14.52 and-14.38). For marketable curd weight and marketable curd yield significantly high GCA effects were recorded in the CMS line Ogu15A (0.11; 0.10) and Ogu13A (5.28; 4.75). Among the ten testers only two genotypes, Kt-2 and EC-162587 had significantly high GCA effect for marketable curd yield. Very high and significant SCA effect has been recorded in the combination Ogu16A × Kt-25 (20.25) and Ogu15A × Kt-2 (19.72) for marketable curd yield. The CMS line, Ogu15A was involved in the most of the heterotic combinations for earliness. Average heterosis was in desirable positive direction for 7 among 14 traits. The range of average heterosis for days to 50% curd maturity was-8.55 to 25.0% and it was-32.04 to 127.91% marketable curd yield. Ogu15A was involved in maximum number of combinations for earliness and higher productivity. Highest heterosis for marketable curd yield was recorded in the combination, Ogu15A × Kt-2 (127.91%), followed by Ogu14A × Sel-26 (90.90%) and Ogu15A × Sel-26 (86.18%). The CMS lines with better combiling ability are involved with most of the heterotic combinations for different traits thus can be used for development of F1 hybrids.