فصلنامه زراعت و اصلاح نباتات
سال پانزدهم شماره 3 (پاییز 1398)

In order to study drought tolerance in barley, two separate experiments were conducted in the form of a randomized complete block design with three replications under normal humidity and rainfed conditions in the research farm of Islamic Azad University, Sanandaj branch in the 2013-2014 crop year. Traits: Grain yield per unit area, day to spike, day to flowering, day to physiological maturity, number of fertile tillers, plant height, peduncle length, spike length, awn length, number of Grains per main spike, plant weight and spike weight were evaluated.The results of analysis of variance under normal and stress conditions indicated a significant difference between cultivars in terms of most of the studied traits.In normal conditions, harvest index and peduncle length and in stress conditions, harvest index and 1000-grain weight showed a positive and significant correlation with grain yield. Stepwise regression analysis showed that under normal moisture conditions, plant weight and peduncle length, and in dryland conditions, plant weight, spike length, day to flowering and day to spike are the most influential traits on grain yield in barley, respectively. Drought tolerance indices of MP, GMP, STI and HM were identified as efficient indices in detecting drought tolerant genotypes with high grain yield potential due to positive and significant correlations with Yp and Ys in barley. Kavir and Zarjoo cultivars with high values of MP, GMP, STI, HM, Yp and Ys indices were recognized as the most drought tolerant cultivars.

This experiment was conducted to study the improvement of biological yield and physiological indicators of Ajwan by application of polyamines under salt stress conditions in 2018. A factorial study was conducted with a randomized complete design with two factors and three replications. The first factor included four levels of water salinity including the control (without salt stress) and salinities of 1000, 2000 and 3000 mg/l. The second factor included five levels of using zero polyamine, 0.5 and 1.5 mmol/l putrescine and 0.5 and 1.5 mmol/l spermidine. The results showed that increasing the salinity levels resulted in a reduction of the height, the biological yield, the lateral branch and the number of umbels in the plant. The lowest amount of chlorophyll a and b and the highest sodium and chloride content in the salt stress of 3000 mg/l was observed. Under salt stress of 2000 mg/l, the spermidine treatment as 1.5 and 0.5 mmol/l led to an increase in the proline content to the amounts of 44.56 and 40.16% as compared with that of the control. Also, the highest peroxidase in the spermidine treatment of 1.5 and 0.5 mmol/l was observed in the amounts of 3.60 and 3.20 micromoles per minute protein. Therefore, the polyamine compounds lead to the reduction of the salt stress effects through improvement in the physiologic characteristics, including increase in the osmotic adjusting compounds and the activity of antioxidant enzymes. Moreover, the polyamine compound of spermidine has a better function than putrescine.

To evaluate some agronomic traits and resistance to diseases and pests in some local rice (Hassani, Anbarboo and Tarom Mahalli) mutants, field experiments were conducted in two locations (Amol and Goldasht) under a randomized complete blocks design with three replications in 2019. Plant material included eight mutant genotypes along with Tarom Mahalli and Shiroodi cultivars as control varieties. Measurements were made on seedling height, plant height, number of fertile tillers, percent of dead heart, leaf blast and sheath blight at vegetative stage. Results showed that at transplanting, five genotypes had lower seedling height than Tarom Mahalli but all genotypes had higher seedling heights than Shiroodi cultivar. The number of tillers in mutants varied between 16.5 to 18.5. The percentage of stem borer damage (dead heart) was 1.7 percent for Tarom Mahalli, which was not significantly different from that of the mutant genotypes. The highest percentage of leaf blast incidence was 5.7% which belonged to mutant 215 and the lowest one was 0.74% in Shiroodi and mutant 3200. The highest percentage of leaf sheath blight among the mutants was 3.5% that belonged to mutant 2310 and was not significantly different from other mutants except for mutants 1120 and 215. Plant height and leaf sheath blight percentage were not affected by location, but number of tillers per plant and blast disease percentage were higher in Goldasht than in Amol. As a result, the relative tolerance of mutants to important pests and diseases was acceptable.

This study was conducted to evaluate the response of 20 durum wheat cultivars native to Khuzestan, available in the collection of the grain research department of the Seed and Plant Breeding Research Institute, to Fusarium blight during the two cropping years 2016-2017 and 2018-2019 in field conditions in two regions. Different, Khuzestan, with two climatic conditions, was implemented. The studied traits included infected clusters, spikelet infestation, seed infestation, cluster density, plant height and biological yield. Cluster analysis was used to measure and determine genetic distances and pattern diversity in wheat Fusarium resistance components of wheat. Evaluation of experimental masses using sporulation method in the field showed that most of the studied masses have a good resistance to the disease in terms of the mean disease index. The cause of resistance seems to have a genetic basis and is related to the presence of type I resistance in them. Twenty durum wheat cultivars can be used as disease-resistant parents in crosses related to wheat breeding programs. The results showed that AYT1 gene is expressed as resistant gene in wheat cultivars. Using PCR technique and SSR molecular markers in this study in order to amplify a single copy or small copies of a DNA fragment with a specific sequence of thousands or millions of copies, to achieve the genetic nature of cultivars, this method can be used as a method. Introduced for the multiplication of resistant genes in this study.

Sweet basil is one of the most widespread spices in the world. Its dried leaves are used commonly as a flavouring in many food products. This experiment was carried out in research farm of Damavand in 2019 to evaluate. Effect of plant density, nitrogen fertilizer and sowing date on yield and chemical composition of essential oil of sweet basil (Ocimum basilicum L.) .The experimental was conducted a factorial using randomized compelet block design with four replication.The factors were three levels of nitrogen fertilizers: N1= application of 50 kg/ha, N2= application of 100 kg/ha, N3= application of 150 kg/ha and three levels of plant densities:P1=5 cm, P2= 10 cm, P3= 15 cm with two sowing date:S1= 25 April, S2= 10 May.In this evaluation, most stage of plant phonology such as plant height, number of leaf, plant dry weight, leaf of stem, leaf area index, yield of essential oil and percentage of methyl chavicol were measured. The results showed that plant height mean with application of 50 kg/ha had superior point and interaction of N3P2S1 was higher than other levels in plant dry weight on the first and second cutting, yield of essential oil on the interaction NS had significant at the 1 % level on the first and second cutting and leaf area index were significant on the intraction of PS and NSP on the first and second cutting %5 level which indicates better performance in nitrogen fertilizer of 150 kg/ha, plant densities of 15 cm and sowing date of 25 April on the first and second cutting.