فصلنامه علوم زراعی ایران
سال بیست و دوم شماره 3 (پیاپی 87، پاییز 1399)

The main purpose of this research was to identify barley promising lines with high grain yield and yield stability for warm region of Iran. In this experiment, 17 barley promising lines and two check cultivars were evaluated in five agricultural research stations; Ahvaz, Darab, Zabol, Gonbad and Moghan, Iran, in 2015-16 and 2016-17 cropping seasons, using randomized complete block design with three replications. Combined analysis of variance showed significant effect of year, year × location and year × location × genotype on grain yield. To identify genotypes with high grain yield and yield satbilty, Lin and Binchr('39')s superiority statistic and GGE biplot analysis method were employed. The lowest values of Lin and Binchr('39')s superiority statistic were for lines No. 2, 3 and 9. GGE biplot analysis revealed that the first and second principle components explained 40% and 24% of total variation, respectively. In this experiment, two mega- environments were identified. The first mega-environment included Ahavaz and Darab, and the second mega-environment included Zabol, Gonbad and Moghan. Considering grain yield and yield stability stability estimates, line NO. 2 has been identified with wide adpatation and released for warm regions (north and south) and line NO. 3 with specific adaptaion for the north warm region of Iran.

To investigate the effect of different planting row ratios of parental lines and agronomic methods on synchronizing of flowering and seed production of SCK703 hybrid maize, a field experiment was carried out as a strip plot arranegemnts in randomized complete block design with three replications in southern Kerman agricukltural and natural rseraech and education center, Jiroft, Iran, in 2015 growing season. In this experiment, vertical factor included maternal:parental row ratios at three levels (4:1, 4:2 and 6:2) and horizontal factor (agronomic techniques) at four levels included: 1. different sowing dates; the first paternal line sown when the maternal’s radicle reached two centimeters and the second paternal line when 50% emergence of maternal line . 2. different sowing depth; sowing depth for the first and second paternal lines were 6 and 8 centimeter, respectively. Maternal line’s sowing depth was 4 centimeter in all treatments 3. seed hydro-priming of maternal line and 4. seed hydro-priming + 10% additional nitrogen. The effect of different planting row ratios of parental lines was significant on seed yield, however the effect of agronomic techniques applied for synchronizing of flowering was not significant. Grain yield was significantly affected by the interaction of planting row ratios × agronomic techniques. The highest seed yield (3620 kg.ha-1) was obtained from 4:2 parental planting row ratios and hydro-priming + 10% additional nitrogen. This package of treatment was not significantly different from the package of treatments of planting row ratio (4:2) and different sowing date and sowing depth with seed yield of 3590 and 3450 kg.ha-1, respectively. Therefore, for easier caliberation of seed sowing machine, it is more practical to sow the first paternal line in six centimeter depth and the second paternal line in 8 cenetmeter depth (the maternal line sowing depth would be four centimeter in all treatments). The maternal:parental planting row ratio of 4:2 is suitable for Jiroft regions in Iran.

To evaluate forage production and land equivalent ratio (LER) in additive and replacement intercropping systems of forage sorghum and berseem clover, a field experiment was conducted using randomized complete block design with eight treatments and three replications at the research field station of Seed and Plant Improvement Institute, Karaj, Iran, in 2016-17 and 2017-18 growing seasons. The experimental treatments consisted of eight intercropping ratios: 75% sorghum + 25% clover (S75C25), 50% sorghum + 50% clover (S50C50), 25% sorghum + 75% clover (S25C75), as replacement intercropping systems and100% sorghum + 50% clover (S100C50), 50% sorghum + 100% clover (S50C100), 100% sorghum + 100% clover (S100C100), as additive intercropping systems, as well as sorghum monoculture (S100C0) and clover monoculture (S0C100). In this experiment, dry forage yield of sorghum and clover, equivalent yield of sorghum and clover, crude protein content, dry matter digestibility, crude protein yield, digestible dry matter yield and LER for dry forage and protein production were evaluated. The results showed that the highest equivalent yield of sorghum, equivalent yield of clover, crude protein, and digestible dry matter yield were obtained from S100C100 treatment with 37598, 17915, 3163, and 17754 kg.ha-1, respectively. S100C50 also ranked in the superior group with 16455 kg.ha-1 of digestible dry matter. The highest land equivalent ratios for dry forage and protein production (1.61 and 1.71, respectively) were calculated for S100C100. S100C50 and S50C100. According to the results of this study, additive intercropping of 100% sorghum + 100% clover can be recommended as the superior intercropping system to meet sustainable agricultural goals in production of these two forage crops.

To improve salinity stress tolerance in Iranian promising alfalfa ecotypes, including Shorkat, Gharghologh, Gharaghozloo, Rehnani, Roodasht Isfahan and Gavkhooni, a recurrent selection scheme was carried out at roodasht and kabootarabad field stations, Isfahan, Iran, during 2012-2017 growing seasons. Six Iranian promising alfalfa ecotypes were planted in the autumn of 2012 and irrigated with saline water of 6 to 15 dS.m-1 during spring and summer of the following year. The ecotypes were evaluated in late summer of the same year using phenotypic characteristics of the plants including; stem no.plant-1, plant height, leaf: shoots ratio, and reaction to pests and diseases, and desirable plants were marked and selected from each ecotype. Seed from selected plants of each ecotype were harvested and bulked. Next year, 13 entries including six selected bulk ecotypes, six Iranian promising ecotypes, and one foreign cultivar (Bulldog) were evaluated using randomized complete block design with four replications. Results showed that derivative ecotypes of Gharaghozloo and Rehnani with average forage production of 80.2 and 79.7 ton.ha-1 fresh forage yield, 19.4 and 19.4 ton.ha-1 dry forage yield and average plant height of 61.3 and 62.3 centimeter, respectively, were salinity tolerant ecotypes. The derivative ecotypes of Gharaghozloo and Rehnani had 19.3% and 19.7% protein content, respectively. These derivatives obtained of 9.5 and 5.5 winter dormancy scores, respectively. They only damaged 10.2% and 7% by weevil. Overall, the derivative ecotypes of Gharaghozloo and Rehnani were identified salt tolerant and are suitable for being grown in saline areas and used in alfalfa breeding programs for development of synthetic alfalfa cultivars.

To estimate genetic parameters of yield and yield component of chickpea, six chickpea genotypes were crossed in complete diallel crossing scheme in glass houses of Seed and Plant Improvement Institute in 2007. Parents, direct and reciprocal crosses (36 entries) were evaluated using randomized complete block design with four replications at Grizeh station, Sanandaj, Iran in spring of 2017 growing season. Plant traits including day to flowering, day to maturity, plant height, seed no.pod-1, pod no.plant-1, drought tolerance score, 100 seed weight and seed yield were measured and recorded during the growing season. Statistical analysis for F1 hybrids and parents as well as diallel analysis were performed using Griffingchr('39')s model 2 of method 1. The results showed that there were significant differences between parents and F1 hybrids, which indicated a wide genetic variability for traits of interest. It was revealed that it would be possible to improve the agronomic traits of chickpea using this genetic resources. Specific combining ability (SCA) was significant for plant height, 100 seed weight and seed yield and the important role of non-additive component in inheritance of these traits was identified. Maternal inheritance had important role in heritability of seed no.pod-1, pod no.plant-1, drought tolerance score and seed yield. Samin" and FLIP 96-154C parents had the highest general combining ability for seed yield, respectively. The effects of specific combining ability revealed that, under conditions similar of this study, Azad × FLIP 96-154C cross was the best specific combiner for seed yield and seed no.pod-1. Considering the results of this study, there was considerable variation in cytoplasmic genes carried by these chickpea genotypes that can be used in breeding for dvelopment of high yielding, with yield stability and early maturity, chickpea cultivars.

To evaluate and select the promising lines of dual purpose grain-forage sorghum under drought stress conditions, a field experiment assplit plot arrangements in randomized complete block design with three replications was carried out atresearch field station of Seed and Plant Improvement Research Institute, Karaj, Iran, in 2014 and 2015 growing seasons. Irrigation levels (60 mm, 120 mm and 180 mm of evaporation from class A evaportation pan) were assigned to main plotsand 10 sorghum lines (KDFGS4, KDFGS6, KDFGS9, KDFGS10, KDFGS12, KDFGS13, KDFGS14, KDFGS16, KDFGS20 and KDFGS21) randomized in sub-plots. Combined analysis of variance showed that irrigation effect was significant (P≤0.01) on plant height and grain yield.  However, irrigation effect was significant (P≤0.05) on dry weight, fresh weight, biological yield and 1000 grain weight. The highest fresh and dry weights of forage was obtained in 60 mm (normal) treatment. The results of biplot multivariate analysis and correlation between droughr indices and grain yield under non-stress and stress conditions showed that MP, GMP, and STI were important in predicting performance of sorghum genotypes. These indices can be used for selecting drought tolerant genotypes. Lines No. 8 (KDFGS16), 1 (KDFGS4), 9 (KDFGS20) and 3 (KDFGS9) were high yielding. The highest correlation coefficients between tolerance indices in stress and non-stress conditions was observed for MP, GMP, STI and YI.. Considering the results of biplot analysis and MP, GMP and STI, sorghum genotypes KDFGS20, KDFGS13. KDFGS14, KDFGS21, KDFGS16, KDFGS4 (lines No. 9, 6, 7, 10, 8 and 1, respectively) were identified drought as tolerant.