Combining Ability and Heterosis for Yield and Yield Components in Maize

Abstract: The study was conducted at two sites , University of Khartoum the experimental farm, faculty of Agriculture, Shambat and at west of Khartoum state, Elrawkeeb Dry Land Research Station, Sudan, during the summer and winter seasons of 2009 and 2010 respectively. Five inbred lines (2, 3, 6, 277, and 405) were used as lines and two inbred lines namely (66Y and 160) were used as (testers). These lines were crossed together according to line x tester technique to generate 10 F 1 -hybrids, every genotype was planted in rows with 4 m along, 70cm between rows and 25cm between plants. A line × tester method for estimation the general combining ability (GCA) of parent and specific combining ability (SCA) of their F 1 -hybrids was used. Genetic components resulting from additive and nonadditive type of gene action were also estimated. Heterosis was measured as a deviation from the midparents and better-parent. The analysis of variance for combining ability revealed that both GCA and SCA variances were highly significant for most of the studied characters indicating importance of additive as well as non-additive types of gene action in controlling these traits. GCA mean squares for inbred lines were significant (P < 0.01) for all the traits except cob length and number of kernels/row while GCA due to testers was only significant (P<0.05) for 100-kernels weight. Moreover, variances due to SCA were higher in magnitude than GCA for the yield and yield components except cob diameter, number of rows/cob, number of kernels/row and harvest index. GCA to SCA ratios were less than one for most of the traits except cob diameter, number of kernels row/cob, number of kernels/row and harvest index indicating a preponderance of additive over no additive gene action. High positive heterosis for grain yield and its components was found for more than half of the hybrids studied. Crosses involving 160×3 and 66Y×2 produced the highest heterosis. It can be concluded that these parental lines can be desirable parents for hybrids as well as for inclusion in breeding program, since they may contribute favorable alleles in the synthesis of new varietie

PHYSICO-CHEMICAL STUDIES OF INDIGENOUS DIURETIC MEDICINAL PLANTS

ABSTRACT Six indigenous medicinal plants have been selected for the physico-chemical studies. These plants belong to Graminaceae, cucubitaceae, cruciferae and Moringaceae families. Colour, taste, pH, density, viscosity, refractive index, specific gravity and optical rotation have been studied in hot water extract of Cymbopogon citratus (DC) stapf where moisture, ash content, acid insoluble matter, fiber content, oil content. Iodine value and Invert sugar studies have been carried out in ethanolic extracts of Citrullus vullgaris, Cucumis melo, Moringa oleifera, Raphanus sativus and Zea mays. Refractive index, specific gravity, saponification value, Iodine value, unsaponiflcable matter and Acid value, colour in lovibond cell have been studied in Raphanus seeds oil

The Effect of Partner Sex: Nondisclosure of HIV Status to Male and Female Partners Among Men who Have Sex with Men and Women (MSMW)

A common concern within HIV prevention is that HIV positive MSMW do not disclose their HIV status to female partners who are thus at increased risk for HIV infection. The present study uses unique data to examine whether MSMW disclose more often to male rather than female partners. Data were collected on most recent male and/or female primary partner and four most recent casual partners from 150 MSMW (50 African American, 50 Latino, 50 White). MSMW reported on 590 partners (31% female; 69% male). Disclosure was coded as disclosure before sex, disclosure after sex, or nondisclosure. A series of multinomial logistic regressions with partners clustered within respondents were conducted to evaluate effects of respondent characteristics and partner characteristics on timing of disclosure. In bivariate and multivariate analyses there were no significant differences in odds of disclosure to male and female partners before or after sex. Although MSMW were substantially less likely to disclose to HIV negative partners before sex compared to HIV positive partners regardless of sex, when we fully interacted the multivariate model by partner sex, the odds of disclosure to HIV negative male partners compared to HIV positive male partners before sex were significantly higher than the odds of disclosure to HIV negative female partners compared to HIV positive female partners. Patterns of mutual nondisclosure and nonreciprocal disclosure were observed with both primary and casual partners. The paper makes additional methodological contributions to the measurement and analysis of disclosure

ALLELOPATHIC INFLUENCE OF CASSIA OCCIDENTALIS L. ON GROWTH OF

The present paper is aimed at evaluating the allelopathic effect of foliar and flower extracts of common wasteland weed Cassia occidentalis L. on seed germination and seedling growth of Zea mays L. The growth of maize seedlings was inhibited significantly by flower and leaf extract treatment of C. occidentalis under laboratory conditions. The effect of flower extracts was more phytotoxic as compared to foliar extracts. A dose-dependent decrease in growth and dry weight of seedlings was observed, however, at lower concentrations, minor enhancement in seedling growth was also observed

OPTIMIZATION ALGORITHM TO

ii ACKNOWLEDGEMENTS I thank our Lord Jesus Christ for giving me the ability to complete this degree. Your love, faithfulness and guidance have been my instruments for this achievement. I would like to thank my husband, Edwin, and my children, Elaisa and Casiano III, for their love, support and understanding while pursuing this degree. I am also thankful to Raun family, and to my relatives, brothers and sisters in Christ and friends for being supportive and helpful in anyway they can. I am also grateful to the Department of Plant and Soil Sciences for granting me the opportunity t

KEYWORDS Grain filling stage Grain yield Stress indices EVALUATION OF MAIZE HYBRIDS TO TERMINAL DROUGHT STRESS TOLERANCE BY DEFINING DROUGHT INDICES

ABSTRACT Terminal drought stress is one of the most important environmental stress factors which can cause a significant reduction in maize productivity. Therefore, to identify the best selection indices for drought tolerance in maize under terminal drought conditions, this research was conducted in two field experiments with some maize hybrids in two cropping seasons (2014 and 2015) under two moisture levels (normal irrigation and water deficit-water stress) at grain filling stage. Results of study revealed that, yield and major yield traits of hybrids adversely affected due to terminal drought stress, it also causing a reduction in productivity with compare normal irrigation conditions. Water stress significantly affected on maize hybrids and there were high variation among hybrids, which could be befits for screening the genotypes. The special attention was paid to hybrids 71May69, Aaccel and Calgary were showed less reduction of grain yield under terminal drought stress. Concerning the genotypes with high stress susceptibility index (SSI) and tolerance index (TOL) were considered as high susceptible to drought and only suitable for irrigated conditions. Accordingly, the positive relationship between stress indices, drought resistance index (DRI) , geometric mean productivity (GMP) , harmonic mean (HM), mean production (MP), stress tolerance index (STI) and Yield index (YI) , and grain yield could be used as the best selection indices for identifying the tolerant hybrids under terminal drought stress

KEYWORDS Deficit irrigation Grain filling stage Starch Oil and protein content NUTRITIONAL QUALITY OF MAIZE IN RESPONSE TO DROUGHT STRESS DURING GRAIN-FILLING STAGES IN MEDITERRANEAN CLIMATE CONDITION

ABSTRACT Maize is considered one of the most essential dietary components in human food and animal feeding. The objectives of the present study were to quantify the effects of drought stress on qualitative traits of maize at grain-filling stages. Hybrids maize seeds were grown by applying full and water stress conditions during the grain filling stage. Various nutritional properties (crude oil, starch, grain protein content) were determined in 2014 and 2015 at the second crop growing season in Adana, Turkey. Based on the results of this study, genotype and environment were found to influence all quality traits significantly. Further, result of study suggest that water stress caused a significant reduction in major quality traits. Grain weight and grain quality yield as well crude oil, protein and ash yield were significantly decreased due to water deficit condition in the both growing seasons. Significant differences were observed among hybrids in respect of all measurements due to irrigation regimes. The genotypes, Sancia and Calgary were tolerant by producing higher grain weight. Accordingly, grain qualities of 71May69, Aaccel and Calgary maize hybrids were less affected under drought stress