Evaluation of 11 cycles of reciprocal recurrent selection in BSSS and BSCB1 maize populations

Eleven cycles of reciprocal recurrent selection (RRS) were conducted in two maize (Zea mays L.) populations, BSSS(R) and BSCB1(R). The objectives were to evaluate the direct and indirect response to selection, combining ability of populations with related and unrelated inbred testers, and effects due to selection and genetic drift on response to selection.;The direct response for grain yield observed in the population crosses was greater than indirect responses observed in the populations per se. The observed rate of response for grain yield was significant in BSSS(R) x BSCB1(R) and BSCB1(R) but a significant response was not observed in the BSSS(R). Changes in other agronomic traits including grain moisture, root and stalk lodging, ear and plant height, and silking and pollen date were generally in desired directions.;The genetic model indicated that selection increased the frequency of favorable alleles affecting grain yield in the improved populations of BSSS(R) and BSCB1(R). The lack of improvement for grain yield observed in both populations was attributed to the effects of inbreeding due to genetic drift. The estimated indirect responses for grain yield, adjusted for effects of genetic drift, were similar to the estimated direct response.;The increased heterosis for grain yield in the interpopulation crosses with cycles of selection was interpreted as resulting from selection for alleles at complementary loci in each population and fixation of different alleles at a locus in each population by genetic drift.;RRS was effective in improving general as well as specific combining ability of the populations, as suggested by the increases in grain yield of the interpopulation crosses and the testcrosses of populations with related and unrelated inbred testers.;The results of this study suggest that RRS is an effective method of selection for improving the population cross. The improved populations can be used as potential germplasm sources in an applied breeding program

Genetic Effects Associated with Reciprocal Recurrent Selection in BSSS and BSCB1 Maize Populations

Reciprocal recurrent selection (RRS) was designed to capitalize on both additive and nonadditive genetic effects for improvement of the cross between two populations by complementary changes in allelic frequencies between populations. Eleven cycles of RRS have been completed in the Iowa Stiff Stalk Synthetic (BSSS) and Iowa Corn Borer Synthetic No. 1 (BSCB1) maize (Zea mays L.) populations. The objectives of this study were to partition the response to selection into that due to additive and dominance genetic effects and to evaluate the effects of genetic drift. A population diallel of the CO, C4, C7, C9, and Cll cycles of BSSS(R) and BSCB1(R) the C8 and C10 inte rpopulation crosses of BSSS(R) and BSCB1(R) were evaluated. The populations per se selfed and interpopulation crosses selfed of the CO, C4, C7, C8, C9, CI0, Cll cycles also were included in the study. The study was evaluated at four locations in 1988 and three locations in 1989. The response of the interpopulation cross for grain yield was 0.28 ± 0.04 Mg ha-1 cycle-1 and was primarily due to dominance effects. Responses in the populations per se, adjusted for the effects of genetic drift, were similar to the direct effects in the interpopulation cross. Improvementin BSSS(R) was due to both additive and dominance effects, but only dominance ffects were important in BSCBI(R). The results showed that selection response occurred at loci with alleles with partial to complete dominance with no evidence for overdominant alleles contributing to selection response. There were no significant changes in grain moisture, and the responses for root and stalk lodging were in the desired direction. It is concluded that RPS was effective for improving the interpopulation cross and inbreeding depression from genetic drift limited the observed response in the populations per se

Statistical screening of factors affecting glucoamylase production by a thermotolerant Rhizopus microsporus TISTR 3518 using Plackett-Burman design

Glucoamylase is a key enzyme used in food processing as well as in commercial production of glucose from starch. The use of thermotolerant strain of Rhizopus microsporus TISTR 3518 offers the advantages of cooling-costs reduction during fermentation and high thermostable enzyme production. The effect of various carbon and nitrogen sources on glucoamylase production was evaluated. It was found that α-amylase treated liquefied cassava starch and CH3COONH4 gave the highest enzyme activity. The influence of various medium components and culture parameters were investigated using Plackett-Burman. It was shown that CH3COONH4, FeSO4.7H2O, ZnSO4.7H2O, CaCl2, temperature and pH are significant factors affecting the glucoamylase production. The medium with the initial pH of 6.5 which consisted of α-amylase treated liquefied cassava starch, 10 gl-1; CH3COONH4, 5gl-1; K2HPO4, 0.5 gl-1; KCl, 1.5 gl-1; MgSO4.7H2O, 0.5 gl-1; FeSO4.7H2O, 0.06 gl-1; ZnSO4.7H2O, 0.035 gl-1; CaCl2, 0.05 gl-1 and C6H8O7.H2O, 5.6 gl-1 yielded the highest enzyme production (948 U ml-1) after cultivation at 40°C for 48 h.Key words: Rhizopus microsporus, glucoamylase, Plackett-Burman design

การพัฒนารูปแบบการบริหารจัดการพลังงานแบบมีส่วนร่วม ในสถานศึกษาอาชีวศึกษา

The objectives of this research were to: 1) develop the collaborative model for energy management in vocational institutes, and 2)develop training courses, evaluate the model appropriateness and the efficiency of the training program. The current vocational institutes situations and needs were surveyed using questionnaire. The surveyed data were analyzed and synthesized to draft a model and be verified by a focus group. A training program was then created from the developed model to manage the energy in vocational institutes efficiently. The results could be concluded as follows: 1) the appropriateness of the developed model, based on the PDCA cycle, was high 2) the evaluation through CIPP model revealed the results as follows: 2.1) the context evaluation presented high congruence between the training topic and objectives with very high appropriateness; 2.2) the input evaluation presented a very high appropriateness and a high congruence in every aspect. The efficiency of the try-out training were 83.45/87.50 and 86.25 for the theoretical and practical parts, respectively; 2.3) the process evaluation reported that the efficiency of the training were 84.50/89.33 and 87.00 for the theoretical and practical parts, which were higher than the set criteria; 2.4) the product evaluation revealed that the training handbook was highly efficient with an excellent appropriateness evaluation result. Trainees and executives could efficiently apply the knowledge and skills from the training program to manage the energy in vocational institutes. In addition, the overall evaluation result was in the level of excellence

Effects of oxyresveratrol and its derivatives on cultured P19-derived neurons

Purpose: To modify the structure of oxyresveratrol and evaluate the obtained derivatives for effects on neuronal cells.Methods: Electron-withdrawing groups were selectively introduced to the aromatic ring of the core stilbene structure. Oxyresveratrol and derivatives were then evaluated for their ability to enhance the survival of P19 derived neuronal cells by XTT method, in comparison with the widely known antioxidants, Trolox and ascorbic acid. Phase-contrast microscopic images of the neurons under various conditions were also taken and analyzed.Results: Oxyresveratrol, at a very low concentration (1 ng/mL), enhanced the survival of neurons in both normal and serum-deprivation conditions. Higher activity was observed for the 5-formylated and t 5-carboxylated products. The potencies of these polyoxygenated stilbenes were far greater than those of Trolox and ascorbic acid. These observations were supported by results from the examination of the phase-contrast micrographs of the neuronal cells.Conclusion: Oxyresveratrol and some derivatives prepared in this study demonstrate significant cell protective activity and may be of therapeutic value, but further investigations in animals are required to verify their neuroprotective potentials.Keywords: Oxyresveratrol, Artocarpus lacucha, Artocarpus lakoocha, Polyoxygenated stilbenes, Cell protection, Neuro