Prakash Singh

Genetic Diversity and Interrelationship of Qualitative and Quantitative Traits in Sweet Potato

Understanding the nature and magnitude of genetic diversity and interrelationship among sweet potato genotypes for traits of economic importance is vital to effective crop improvement. Genetic variability, character association, path coefficient, and genetic diversity analysis for 17 qualitative and quantitative traits in 20 diverse sweet potato genotypes was undertaken. A wide range of genetic variation occurred for tuber yield per plant, carotene content, starch content, fresh weight of tubers per plant, and numbers of branch per plant. Fresh weight of tuber per plant had a positive phenotypic correlation with number of tubers per plant followed by days to maturity and vine internode length. Total carotene content had a positive significant association with vine length, number of leaves per plant, and number of branches per plant. Days to maturity had a positive phenotypic correlation with vine length, vine internode length, and number of leaves per plant. At the genotypic level the highest, positive, direct effect on fresh weight of tubers per plant was due to dry matter content and days to maturity followed by moisture content via numbers of tubers per plant and total sugar content. Cluster analysis divided genotypes into two main groups, indicating a genetic relationship among accessions. The genetic variability and traits relationship could provide new avenues to breed improved sweet potato.

Synthesis, microstructure and electrical properties of Ti doped SrSnO3

Abstract Samples in the system SrSn1−xTixO3 were prepared by conventional solid state ceramic route for 0≤x≤0·50. Powder X-ray diffraction was performed to confirm formation of single phase solid solution. It has been found that solid solution forms only up to x=0·40. DC resistivity and Seebeck coefficient α were measured to understand electrical conduction behaviour. It has been observed that in all the compositions electrons are the major charge carriers. Scanning electron micrographs were taken to study the microstructure. It has been found that grain size is in the range of 1–5 μm. Based on the results of α and activation energy E a of DC conduction, it is proposed that conduction occurs due to migration of O2− ions through oxygen vacancies V∞O for all the compositions.

Genetic Diversity for Seed Yield, Its Components and Oil Content in Indian mustard (Brassica juncea L. Czern and Coss.) under Normal and Saline/Alkaline Condition

Indian mustard [Brassica juncea (L.) Czern & Coss], which is cultivated under the genus Brassica is cultivated all over India and it is throughout the world belongs to family Cruciferae (Brassicaceae). It has 38 to 42 % oil and 24% protein. Among rapeseed and mustard, rai (B. juncea) is very popular among the farmers due to higher yield and greater tolerance against lodging, shattering, drought condition, heat and relative diseases as well as International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 7 Number 06 (2018) Journal homepage: http://www.ijcmas.com

Evaluation of genetic divergence and heritability in urdbean [Vigna mungo (L.) Hepper]

A field experiment was conducted to examine the genetic divergence and heritability among 109 urdbean genotypes. Significant genotypic differences were observed for all the quantitative traits studied, indicating the considerable amount of variation among the genotypes for twelve characters. High heritability (bs) estimates (> 80%) coupled with high genetic advance (%) of mean were seen for most of the yield contributing traits showing additive gene effect. The genetic diversity analysis was done by employing non-hierarchical Euclidean cluster analysis. It revealed wide range of D2 values (57.57 to 7358.48) suggesting the presence of marked amount of genetic diversity among genotypes; which were grouped into eleven clusters. Cluster IV (18) and XI (18) were having the maximum genotypes followed by cluster I (15) and cluster V (12). The maximum and minimum inter cluster distance were recorded between II and IX (7358.48), and X and XI (170.83), respectively representing wide divergence among these clusters. It is suggested that the crosses should be made between genotype of cluster IV, VIII, IX and XI for enhancing the yield potential of crop as well as improving important economic traits to develop a high yielding variety or cultivar in future breeding programme.

DIELECTRIC BEHAVIOUR OF MANGANESE MODIFIED STRONTIUM TITANATE CERAMICS SYNTHESIZED BY SOLID STATE CERAMIC ROUTE

Various compositions with x=0.01, 0.05, 0.10, 0.20 and 0.30 in the system SrTi1-xMnxO3 were prepared by solid state ceramic route. Compositions with x ≤ 0.10 were found to be single phase solid solution. In this paper, the result of investigations on the effect of manganese substitution in SrTiO3 on dielectric behaviour for the compositions with x ≤ 0.10, which form single phase solid solution have been reported. Average grain size is small, this may be due to segregation of dopant at grainboundaries. Dielectric measurements were made in the temperature range 150–500K. Measurements of dielectric properties show that there is not much space charge polarisation across the grains and grainboundaries interface. This space charge polarisation only occurs at high temperature and one observes large dispersion of dielectric constant and dissipation factor. At low temperatures, dielectric behaviour follows the character of SrTiO3 with only difference in the values of dielectric constant.