Diversity analysis of Sweet Potato (Ipomoea batatas[L.] Lam) genotypes using morphological, biochemical and molecular markers

276-285Sweet potato [Ipomeabatatas(L.) Lam.]is a nutritious food crop primarily grown by small and marginal farmers. Successful breeding and germplasm conservation programs demands characterization of its germplasm. Here, we tried to determine genetic diversity among 21 sweet potato genotypes using morphological, biochemical and molecular markers. Ten morphological traits were studied and subjected to analysis of variance (ANOVA). Mean square due to germplasm were highly significant as well as wide mean range performance was observed for tuber number per plant, individual tuber weight, tuber fresh yield per plant, tuber dry yield per plant, tuber yield per plot and tuber length. UPGMA (Unweighted Pair Group Method Arithmetic Average) cluster analysis based on morphological traits separated the germplasm into three groups. The genotypes Gautam, Shree Arun, RS-92 and CO-3-4 appeared promising with regard to yield characters. Total phenol was maximum in in V-12 genotype (1.39 mg), while minimum was recorded in Samrat genotype (0.95 mg). The highest total antioxidant was observed in the genotype Samrat (0.30 mg), while minimum was recorded in the genotype Navsari Local (0.16 mg). Molecular diversity analysis was carried out using 25 RAPD (Random Amplified Polymorphic DNA) primers, out of which 13 primers produced 117 reproducible amplicons (106 polymorphic, 7 monomorphic and 4 unique amplicons). UPGMA dendogram based on RAPD data separated the genotypes into two major clusters having the similarity coefficient ranged from 0.56 to 0.76. The results can be used for sweet potato crop improvement through molecular breeding and marker assisted selection of for desired traits in future

Heterosis breeding for quality improvement in tomato (Lycopersiconesculentum Mill.) for cultivation in mid hills of Uttarakhand

Tomato (SolanumlycopersicumL.), an annual vegetable,second in production after potato of solanaceae family. Tomato is number one in processed vegetables. For the improvement in the genetic architecture, Heterosis breeding is most popular and successful approach in tomato. For the present study, six diverse tomato cultivars viz, ArkaSaurabh, ArkaAbha, ArkaMeghali, Punjab Chhuhara, Best of All and Sioux, selected on the basis of high yield coupled with high quality, were crossed in a half diallel fashion to obtain fifteen cross combinations. Three cross combinations viz, ArkaMeghali x Punjab Chhuhara, ArkaSaurabh x ArkaAbha and ArkaSaurabh x Punjab Chhuhara resulted in significantly positive heterosis over mid parent, better parent, for pericarp thickness. For total soluble solids, positive and significant heterosis over mid and better parents were observed in three cross combinations viz,ArkaSaurabh x ArkaMeghali, Punjab Chhuhara x Best of All and ArkaMeghali x Sioux. Best of All x Sioux and Punjab Chhuhara x Sioux showed highest significant positive heterosis over mid parent and better parentfor shelf life. While, for one of the most important quality trait lycopene content, ArkaSaurabh x ArkaMeghali, ArkaSaurabh x Punjab Chhuhara, ArkaSaurabh x Best of All and ArkaAbha x Best of All resulted in significantly positive better parent and mid parent heterosis.ArkaSaurabh x ArkaMeghali was the best cross combination for Lycopene content and total soluble solids