Stress tolerance in cabbage

B. K. Singh, S. R. Sharma, Chandra Prakash, R. N. Barwal and M. R. Dhiman

ICAR News: A Science and Technology Newsletter 17 (2): 2-3, 2011

E-mail: bksinghkushinagar@yahoo.co.in

            Production of deleterious reactive oxygen species (ROS) such as singlet oxygen (¹O₂), superoxide radical (^●O^-₂), hydrogen peroxide (H₂O₂), hydroxyl ion (OH^-) and free hydroxyl radical (^●OH) is one of the reasons for poor productivity and quality of the harvest under stressful conditions in cabbage. Plants possess well-developed defense systems against deleterious ROSs by limiting their formation and by triggering for their removal. If ROSs are not neutralized, they damage cells, causing susceptibility to biotic and abiotic stresses, yellowing and senescence. Pre-mature senescence leads to loss of vigour, productivity and quality of produce. Antioxidant enzymes- superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT)- have touted as beneficial for mitigating effects of oxidative stresses induced by ROSs. SOD, localized in cytosol, chloroplast, mitochondria and peroxisomes, accelerates the dismutation of ^●O₂^- to H₂O₂. POX, an iron heme protein, catalyses H₂O₂ reduction with a concurrent oxidation of a substrate, mostly located in cell wall, and is involved in the oxidation of phenol compounds towards lignin synthesis. CAT also catalyses H₂O₂ reduction to water and molecular oxygen, and is localized in mitochondria and peroxisomes, and absent in chloroplast. This study determined variability for enzymes SOD, POX and CAT activities, and their inheritance was studied in the cabbage samples harvested at the fresh marketable stage, frozen immediately in liquid nitrogen and placed at -80 ⁰C for assay. Enzymatic antioxidant activities showed 1.6, 12.8, and 18.2-fold difference for SOD, POX and CAT, respectively. Red Cabbage, 83-2, KIRC-1-1, ARU Glory, Kinner Red, MR-1, AC-208, Red Rock Mammoth, KIRC-8 and KIRC-1A showed higher activity of antioxidant enzymes. All enzymatic antioxidants expressed high heritability along with low genetic advance as percentage of mean indicated the predominance of non-additive genes, and provide good prospects for hybridization and hybrid breeding. The results indicate that breeding of antioxidant potential cultivars will enhance the stress tolerance ability of cabbage and will result in healthy plant stand, and thus eventually mitigate climate change effects in cabbage cultivation.

Genetic combining ability for concentration of mineral elements in cabbage head (Brassica oleracea var. capitata L.)

B. K. Singh, S. R. Sharma and B. Singh

Euphytica 184 (2): 265-273, 2012

E-mail: bksinghkushinagar@yahoo.co.in

Abstract

Brassica vegetables are important source of dietary nutrition. However, information on the genetic combining ability of mineral elements such as iron, zinc, copper, manganese, potassium and calcium or their types of genetic effects (i.e. additive or non-additive) is scarce but important as it influences the selection of parents and breeding approaches to be adopted for improvement of nutritional quality of cabbage. Therefore, an attempt was made to estimate combining ability in a line × tester (5 × 11) mating design for minerals. Significant mean square for line × tester interaction was observed for all minerals under study indicating the prevalence of non-additive variance; while less than unity value of σ²_gca /σ²_sca ratio for iron, zinc, manganese, potassium and calcium accumulation indicate predominance of non-additive gene action. The parents 83-2, Pride of Asia, Pusa Mukta, Red Cabbage and MR-1 were found good general combiners for four mineral elements. The general combining ability effects of the parents for various minerals revealed that none of the parents excelled for all the minerals suggesting the need for multiple crossing approaches. The cross 83-1 × AC-1019 (Poor × Poor general combiner) exhibits desirable significant specific combining ability effects for all six minerals might be due to presence of high magnitude of non-additive especially complementary epistatic effects which can be utilize for commercial exploitation of heterosis. This study shows clearly that specific combining ability is more important than general combining ability for predicting hybrid combinations for high mineral content in cabbage head.

Key words: Brassica, micronutrient, macronutrient, human health, biofortification. 

Combining ability for antioxidants and economic traits in cabbage (Brassica oleracea var. capitata L)

B. K. Singh, S. R. Sharma and B. Singh

Indian Journal of Horticulture 68 (4): 490-497, 2012

bksinghkushinagar@yahoo.co.in

ABSTRACT

Fifty-five cross combinations along with their sixteen parents were transplanted in randomized block design to generate information on combining ability of antioxidants and economic traits in cabbage. The significance of mean squares of parents and line x tester interactions revealed the pervasiveness of additive and non-additive variance. Non-additive gene action was found to be predominant for carotenoid content, early maturity, frame spread, gross plant weight, net head weight, core length, harvest index, and head compactness, nevertheless additive genes were responsible for synthesis of ascorbic acid and expression of non-wrapper leaves in desirable direction. Golden Acre was found to be good combiner for seven economically important traits viz., carotenoid, earliness, net head weight, number of non-wrapper leaves, polar and equatorial diameter, and core length. Among 55 cross combinations, Pride of Asia × Red Cabbage, CMS-GA × AC-1019, CMS-GA × EC-490192, and Golden Acre × AC-1021 were most outstanding as indicated by respective high SCA effect. Majority of the cross combinations exhibited desirable SCA effects for various traits and involved at least one of the parents as poor general combiner, which signifies the greater importance of SCA than GCA in predicting hybrid combinations for desirable traits and scope for heterosis breeding for improving the traits of nutrition and economic importance.

Key-words: Carotenoid, ascorbic acid, cabbage, nutrition, GCA, SCA.