Authors:A. Etminan, A. Pour-Aboughadareh, R. Mohammadi, L. Shooshtari, M. Yousefiazarkhanian, and H. Moradkhani
In the present study, efficiency of the artificial neural network (ANN) method to identify the best drought tolerance indices was investigated. For this purpose, 25 durum genotypes were evaluated under rainfed and supplemental irrigation environments during two consecutive cropping seasons (2011–2013). The results of combined analysis of variance (ANOVA) revealed that year, environment, genotype and their interaction effects were significant for grain yield. Mean grain yield of the genotypes ranged from 184.93 g plot–1 under rainfed environment to 659.32 g plot–1 under irrigated environment. Based on the ANN results, yield stability index (YSI), harmonic mean (HM) and stress susceptible index (SSI) were identified as the best indices to predict drought-tolerant genotypes. However, mean productivity (MP) followed by geometric mean productivity (GMP) and HM were found to be accurate indices for screening drought tolerant genotypes. In general, our results indicated that genotypes G9, G12, G21, G23 and G24 were identified as more desirable genotypes for cultivation in drought-prone environments. Importantly, these results could provide an evidence that ANN method can play an important role in the selection of drought tolerant genotypes and also could be useful in other biological contexts.
Authors:M. Barati, M.M. Majidi, A. Mirlohi, M. Safari, F. Mostafavi, and Z. Karami
The vast genetic resources of wild barley (Hordeum vulgare ssp. spontaneum, hereafter WB) may hold unique assets for improving barley (H. vulgare ssp. vulgare) cultivars for drought stress. To evaluate genetic potential and characterization of variation among a diverse collection of barley and WB genotypes, mostly originated from Iran, a field experiment was performed under three moisture environments (control, mild and intense drought stress) during two years (2012–2014). Considerable variation was observed among the wild and cultivated genotypes for drought tolerance and agronomic traits. Principal component analysis (PCA) grouped genotypes studied into three groups (WB, two-row barley and sixrow barley groups). However, Iranian and foreign WB genotypes were not completely separated, showing a high variation within both gene pools. The high significance of genotype by environment interaction, confirms importance of using accurate target environments for drought stress breeding. A number of WB genotypes with the highest values of the number of tillers, number of seed per spike, seed weight, grain yield and yield stability index under stressed environments were identified as superior genotypes. Most of these genotypes originate from Iran, highlighting the importance of this germplasm in barley breeding.
Wheat with its advantages of high yield stability, well-mastered crop management and the possibility of long-term storage is suitable for ethanol production. Ethanol production has to be cost-effective and, therefore, wheat used in production should have a high potential for ethanol production. Previous works showed that low-nitrogen grain content is important for the relative ethanol yield and the agronomic yield for the absolute ethanol yield per area is important. In this work, importance of grain nitrogen and starch content for ethanol conversion efficiency was verified. Furthermore, environmental effects in relation to the ethanol conversion efficiency and ethanol yield in conditions of Central Europe were studied. With regard to the environmental factors, the annual rainfall sum was found to be the most important factor for ethanol conversion efficiency, while the grain yield was found to be the most important factor for the ethanol yield. On the basis of these findings it can be considered that wheat varieties possessing high yields of low protein grain planted in areas with higher rainfall amount would be ideal for the production of ethanol.