ABSTRACT
Aim: Development of commercial hybrid of sunflower on basis of best inbred combination remains a key challenge to sunflower breeders. In the current investigation, heterosis of F1 hybrids, parental genetic diversity and correlation between genetic distance and level of heterosis were estimated. Methodology: Thirty five parental genotypes (3 CMS A lines and 32 R lines) and their hybrids were assessed for physio-morphological, yield and quality traits. Heterosis was measured as mid-parent and better parent heterosis. Among parents, SSR marker based genetic distances were calculated using DARwin software. Correlation between heterosis and genetic distances was carried out by Karl Pearson’s simple correlation method. Results: Range of genetic distances, based on SSR marker analysis, varied from 0.32-0.73. Genetic distance had significant positive correlation with the heterosis for oil content (r = 0.22 p<0.05) and linoleic acid (r = 0.32 p<0.05), but negative correlation was observed for days to maturity, test weight, volume weight, stearic acid and oleic acid. There was no significant correlation between genetic distance and heterosis for seed yield and other agronomic traits. Interpretation: Although, genetic distance is poor predictor of heterosis, dependence of oil content on genetic distance among parental lines may be used for designing an effective breeding program for sunflower.
ABSTRACT
The present study attempted to establish appropriate cut off levels of Body Mass Index (BMI) for defining overweight as a risk for the development of type 2 diabetes considering percentage body fat (BF) as standard. A total of 300 patients of known type 2 diabetes participated in the study (150 males and 150 females, all > or = 40 years of age). Clinical examination was done. Anthropometric measurements as BMI, Waist Circumference (WC) and Waist-hip ratio (WHR) were calculated. Percentage BF was calculated using skinfold thickness method from the equation of Durnin and Womersley. Mean BMI for males was 24.97 (SD 4.3) kg/m2 and for females was 27.56 (SD 5.14) kg/m2. Mean percentage BF for males was 28.19 (SD 0.74) and for females was 38.22 (SD 5.29). A comparison of BF and BMI data with various ethnic groups revealed conspicuous differences. Receiver operating characteristic (ROC) curve analysis showed a low sensitivity of conventional cut off value of BMI (25 kg/m2) in identifying subjects with overweight as compared to the cut off values based on percentage BF (males > 25, females > 30). This results in substantial misclassification. Based on the ROC curve, a lower cut off value of BMI 22.3 kg/m2, displayed the optimal sensitivity and specificity, and less misclassification in identification of type 2 diabetics with high percentage BF. BF: BMI was calculated and was found to be higher in females.