Molecular diversity of Pakistani mango (Mangifera indica L.) varieties based on microsatellite markers.

Understanding the genetic diversity of different Pakistani mango varieties is important for germplasm management and varietal characterization. Microsatellites are efficient and highly polymorphic markers for comparative genome mapping, and were used in the present study to determine the genetic relatedness and variability among 15 indigenous mango cultivars (Mangifera indica L.). Overall, 181 bands were produced using 12 simple sequence repeat (SSR) primers. Out of the 12 primers used, 10 were polymorphic and two were monomorphic. Genetic relatedness among cultivars was assessed by constructing a dendrogram using the unweighted pair group method of arithmetic means. The accessions exhibited coefficients of similarity ranging from 75 to 100%, indicating the frequent use of only a few parent cultivars and the presence of inbreeding. The primers used in the present study were found to be valuable for identifying genetic relationships among mango cultivars.

Assessment of genetic diversity of cotton genotypes for various economic traits against cotton leaf curl disease (CLCuD).

In Pakistan, cotton crop has been under enormous threat of cotton leaf curl disease (CLCuD) over the last four decades. In order to estimate genetic diversity in cotton germplasm CLCuD resistance, we assessed 100 cotton genotypes for their CLCuD resistance/tolerance and other related agronomical traits. Various statistical analytical tools, including correlation analysis, cluster analysis, and principal component analysis (PCA), were used to select the best genotypes. These genotypes can be used in future breeding programs to generate CLCuD resistant varieties. The same set of procedures could be utilized for other diseases in other crops. CLCuD incidence showed a significant negative genotypic correlation with yield-contributing traits followed by a significant negative association for phenotypic correlation. The seed cotton yield showed significant positive genotypic and phenotypic correlations with plant height, number of bolls per plant, and boll weight. From the PCA we identified five principal components (PCs) that explained a significant amount of the variance among the variables, which may be used for selection of cotton genotypes with CLCuD resistance. Of the five PCs, the first four contributed more towards the total variability and had eigenvalues greater than one. The cluster analysis showed that the genotypes in one of the clusters performed particularly well with respect to CLCuD tolerance. These genotypes can be utilized for development of varieties with increased CLCuD tolerance.

Estimation of genetic variability among peanut genotypes for resistance to leaf spot disease.

This study aimed to identify high-yielding peanut genotypes with resistance to leaf spot disease. The experiments included material from fourteen local and four exotic peanut genotypes that showed highly significant differences among morphological and disease severity parameters in all the genotypes which, in turn, suggested diversity genotypes. Disease severity analysis showed that the highest disease score and damaged leaf area were observed in the genotype Kelincer and the lowest scores and leaf damaged areas were observed in Majalaya super and BARI-2000, respectively. Based on these results, the genotypes BARI-2011, Chakori, Golden, BARI-89, Majalaya Super, BARD-699, BARI-2000, SP-1, and No. 334 can be used by breeders in peanut improvement programs for the development of new cultivars with higher disease resistance and increased yield.

Heterosis and correlation in interspecific and intraspecific hybrids of cotton.

Interspecific and intraspecific hybrids show varying degrees of heterosis for yield and yield components. Yield-component traits have complex genetic relationships with each other. To determine the relationship of yield-component traits and fiber traits with seed cotton yield, six lines (Bt. CIM-599, CIM-573, MNH-786, CIM-554, BH-167, and GIZA-7) and three test lines (MNH-886, V4, and CIM-557) were crossed in a line x tester mating design. Heterosis was observed for seed cotton yield, fiber traits, and for other yield-component traits. Heterosis in interspecific hybrids for seed cotton yield was more prominent than in intraspecific hybrids. The interspecific hybrid Giza-7 x MNH-886 had the highest heterosis (114.77), while among intraspecific hybrids, CIM-554 x CIM-557 had the highest heterosis (61.29) for seed cotton yield. A major trait contributing to seed cotton yield was bolls/plant followed by boll weight. Correlation studies revealed that bolls/plant, boll weight, lint weight/boll, lint index, seed index, lint/seed, staple length, and staple strength were significantly and positively associated with seed cotton yield. Selection based on boll weight, boll number, lint weight/boll, and lint index will be helpful for improving cotton seed yield.

Diallel cross analysis of plesiomorphic traits in Triticum aestivum L. genotypes.

We conducted a 5 x 5 complete diallel cross experiment in bread wheat (Triticum aestivum) with the genotypes 6309, Chkwal-50, Dhrabi, Bhkhar-02, and FS-08. Our objective was to evaluate the type of gene action and the general and specific combining abilities required for various morphological traits in wheat. The results of analysis of variance revealed highly significant differences among genotypes for all the investigated traits. The results of joint regression analysis showed that the data for all the investigated traits fitted a simple additive dominance model. Graphical representation of variance and covariance suggested that most of the investigated traits were controlled by overdominance gene action. However, the peduncle length and plant height were controlled by additive gene action. Variety 6309 carried the highest number of dominant genes for the number of spikelets per spike, number of tillers per plant, plant height, number of fertile tillers per plant, and grain yield per plant. Chakwal-50 carried the highest number of recessive genes for grain yield per plant, number of tillers per plant, number of grains per spike, number of fertile tillers per plant, and plant height. Chakwal-50 and 6309 were the best general combiners for number of spikelets per spike, number of grains per spike, grain yield per plant, 1000-grain weight, number of fertile tillers per plant, and number of tillers per plant. On other hand, 6309 performed well in specific crosses with Chakwal-50, FS-08, and Bhakhar-02 for spike length and number of tillers per plant.

Estimating genetic potential of biofuel forest hardwoods to withstand metal toxicity in industrial effluent under dry tropical conditions.

Biofuel tree species are recognized as a promising alternative source of fuel to conventional forms. Additionally, these tree species are also effective in accumulating toxic heavy metals present in some industrial effluents. In developing countries such as Pakistan, the use of biofuel tree species is gaining popularity not only for harvesting economical and environmentally friendly biofuel, but also to sequester poisonous heavy metals from industrial wastewater. This study was aimed at evaluating the genetic potential of two biofuel species, namely, Jatropha curcas and Pongamia pinnata, to grow when irrigated with industrial effluent from the Pak-Arab Fertilizer Factory Multan, Southern Punjab, Pakistan. The growth performances of one-year-old seedlings of both species were compared in soil with adverse physiochemical properties. It was found that J. curcas was better able to withstand the toxicity of the heavy metals present in the fertilizer factory effluent. J. curcas showed maximum gain in height, diameter, and biomass production in soil irrigated with 75% concentrated industrial effluent. In contrast, P. pinnata showed a significant reduction in growth in soil irrigated with more than 50% concentrated industrial effluent, indicating that this species is less tolerant to higher toxicity levels of industrial effluent. This study identifies J. curcas as a promising biofuel tree species that can be grown using industrial wastewater.

Clinicopathological study of exfoliative dermatitis.

A clinicopathological study of exfoliative dermatitis involving 25 fresh cases was carried out. Males were predominantly affected with a peak incidence between 21-30 years. Pruritus, shivering, erythema and scaling were the common clinical manifestations. Psoriasis and eczema were the most common aetiological factors and the histopathological findings were correlating with the same.

A prospective study of the effects of lithium on thyroid function and on the prevalence of antithyroid antibodies.

Tests of thyroid function and pathology were carried out on 133 patients before they were treated with lithium (Li+). Of the 12 patients who subsequently became hypothyroid during treatment with lithium 9 had, before the commencement of treatment, thyroid autoantibodies and/or an exaggerated thyroid stimulating hormone (TSH) response to thyrotropin releasing hormone (TRH), whereas 3 patients had neither of these indicators. Lithium administration was accompanied by a rise in thyroid antibody titre in 20 patients but a fall in only 5, a statistically significant difference. Evidence that it may be an immunostimulant is discussed. Li+-induced thyroid failure cannot be accurately predicted, and may occur suddenly. The best minimum safeguard, therefore, is serial thyroxine (T4) (or free T4) estimation, supplemented if equivocal by a free thyroxine index (FTI), a basal TSH and, if doubt remains, by a TRH test.

Demographic crisis: The impact of the Bangladesh civil war (1971) on births and deaths in a rural area of Bangladesh.

Summary In Matlab Bazaar Thana the Cholera Research Laboratory has registered the births, deaths and migrations in a population of approximately 125,000 since 1966. Although this rural area was not the scene of any significant armed encounters, striking changes in birth and death rates were registered during and after the conflict. Birth rates did not change during the relatively brief period of the civil war, but a small decline was registered for one year after the war. Fertility rates which had been declining slightly and irregularly in the pre-war baseline period may have increased slightly during the war and fell substantially in all age groups in the year following the war. The crude death rate, which rose by 37 per cent during the war, was a very sensitive reflection of the administrative and economic problems. Overall infant mortality rose by only 15 per cent over pre-war levels because all of the increase was observed in the post-neo-natal component, which traditionally accounts for less than one-third of the total infant mortality in Bangladesh. Children and older adults accounted for the majority of excess deaths which were largely attributed to acute diarrhoeas and other gastro-intestinal causes. The death rate at ages 1-4 rose by 43 per cent and at ages 5-9 soared to 208 per cent above pre-war baseline rates. All increases in age-specific mortality rates fell to baseline levels during the year following the war, except the 5-9-year age group, in which rates continued to be high largely because of deaths due to dysentery.