RESUMEN
Spodoptera litura (Fabricius, 1775) is a serious polyphagous pest causes serious damage to various crops like tobacco, cotton, cabbage etc. in Asia and other Indian subcontinents. Depletion in host plants may lead to adverse effect on the alternate host plants. During survey, observed S. litura larvae were feeding on Cassia tora, in this study third instar larvae of S. litura larvae were reared on the common and most preferred hosts like castor and tobacco. Larval, prepupal and pupal weight were compared with and other two common hosts. Percent pupation and adult emergence rate were also recorded. Among three hosts, insects which fed on Cassia tora have higher larval weight (0.825 mg) and also observed longer larval period compared to other two hosts. No differences were observed in prepupal, pupal (male and female) weight. Percent pupation was higher in S. litura, which were fed on castor and tobacco i.e., 100 % and 96.67 % respectively, and on C. tora recorded lowest per cent pupation (20 %). Adult emergence rate was found to be non-significant on castor and tobacco fed larvae but the lowest adult emergence was recorded on cassia about 18 %. Feeding of newly hatched instars of S. litura confirms that, it uses C. tora as an alternate host during off-season survival and complete its life cycle. Longer larval duration on C. tora may prone larvae to expose more to the external environment, results in less pupation rate.
RESUMEN
The selection of breeding material heavily relies on genetic variation and its inherited components. A thorough understanding of genetic variation is necessary in order to develop an improved variety. Thus, genetic parameters were assessed in the F2 population of the cross between DDK-1029 and GPM DIC 66. The genetic variability results indicated a moderate to high phenotypic and genotypic coefficient of variation for characters like days to 50% flowering, plant height, productive tillers per plant, spike length, spikelets per spike, grains per spike, thousand grain weight and grain yield. In contrast, the protein, iron and zinc contents exhibited low to moderate phenotypic and genotypic coefficient of variation. All the traits had higher heritability except for grain yield which exhibited a moderate heritability. All the characters exhibited significant GAM except for days to maturity, iron content and protein content which exhibited moderate GAM. This suggests that high genetic variation, heritability, and GAM for such traits will aid in their improvement through both direct and indirect selection.
RESUMEN
Salinity stands out as a crucial abiotic stress factor that significantly impacts both crop yield and quality. Wheat, considered a moderately salt-tolerant crop, offers a wealth of variability and diversity within its species, presenting an accessible avenue for enhancing wheat's salt tolerance. Consequently, this study investigated the extent of genetic diversity for salt tolerance among sixty Triticum dicoccum germplasm accessions. In both saline and control condition, the genotypes were divided into three and nine separate clusters respectively, showing that there was a significant level of genetic variability among the genotypes by multivariate analysis. It was observed that biomass was the largest contributor (85.19 %) to the divergence in the saline situation. Among the yield parameters under saline condition, tillers per meter followed by thousand-grain weight and spike length were observed to be important. Thirteen genotypes were salt-tolerant, according to the Stress susceptibility index (SSI). The stress tolerance index (STI) was defined as a useful tool for determining the high yield and potential stress tolerance of genotypes. Based on the stress tolerance index, only eight genotypes were said to be tolerant.
RESUMEN
Salinity is one of the most important abiotic stresses affecting crop yield and quality. Wheat is regarded as a moderately salt tolerant crop; wheat species exhibit high variability that can be conveniently explored to improve wheat species for salt tolerance. Hence, the magnitude of variability for salt tolerance was studied in dicoccum wheat germplasm accessions. High phenotypic and genotypic coefficients of variance were observed for grain yield and yield attributes like tillers per meter, biomass, spikelets per spike and harvest index. The heritability and genetic advance over mean were moderate to high for grain yield, thousand grain weight, tillers per meter, biomass, spikelets per spike, harvest index, plant height, days to 50 per cent flowering and days to maturity. Character association studies revealed that harvest index and SPAD at anthesis stage exhibited a positive significant correlation under both saline and control condition. Path coefficient analysis revealed that traits like harvest index, biomass, tillers per meter and days to 50 per cent flowering were showing a high direct effect on grain yield under both saline and control condition. Thus, the present study provides valuable genetic resources for grain yield and yield parameters improvement which are associated with the salt tolerance in wheat species.