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The possible role of chitinase in in vitro growth inhibition of the wheat pathogens Fusarium graminearum and Bipolaris sorokiniana by Bacillus pumilus SG2 was investigated. B. pumilus SG2, a chitinolytic bacterium producing two different chitinases, was previously isolated from the saline deserts of Iran. When grown in Spizizen salts medium with colloidal chitin, B. pumilus SG2 secreted two chitinases into the medium, resulting in growth inhibition of F. graminearum and abortion of hyphal elongation of B. sorokiniana. In contrast, when glucose was used as the carbon source, the chitinases were not expressed and antifungal activity of the B. pumilus SG2 was completely abolished. These results confirmed that expression of the B. pumilus SG2 chitinases is under the control of two types of regulation, special regulation by chitin and global regulation by glucose. We demonstrated that chitinases are the main components that caused hyphal inhibition activity of B. pumilus SG2. Hyphal inhibition of F. graminearum and B. sorokiniana was stable in agar for a minimum of 14 days.

This research was conducted to study effects of G × E interaction on 38 selected genotypes of cotton with two commercial cultivars Golestan and Sepid (control) in a randomized complete block design with three replications at three locations in Golestan Province in 2014-15. The measured characteristics were included: plant height, sympodial length, sympodial number, boll number, boll weight, seed cotton yield and earliness. Analysis of variance showed that genotype effect is significant in 1 or 5% probability levels on measured traits except for boll number and earliness. A significant interaction effect between genotype × locations in yield showed different variation trends in various locations. So that genotype 29 had the best performance in Hashemabad station but genotypes 24 and 18 showed their best performances in Gonbad and Anbarolum station respectively. Stability parameters were calculated and genotype No. 8 was defined according to regression slope close to 1 as the most stable genotypes among. This genotype had a smaller share in genotype and environment interaction according to Rick ecovalans and Shukla stability variance parameters and 10 and 33 were the most unstable genotypes in terms of performance. GGE biplot method showed that the first two principal components regression model explained 74% of the observed changes. GGE biplot graph plotted by software reflected the superior genotypes TJ82, ER26, DB29, DB19, DB25 and ER36 respectively. Also Hashemabad has been identified as appropriate region for ER26 genotype and TJ82 was identified as the best and most stable genotype.

In order to estimate combining ability and gene action of a number of rice cultivars, a 5 x 5 half a diallel cross genetic design has been used. Parents and their hybrids have been evaluated in a randomized complete block design with 3 replicates for yield and 6 yield components in 2007 in Rice Research Station of Iran-Amol. Mean squares of genotypes for all traits were highly significant (p < 0.01). Significant mean squares of combining ability for all traits showed additive and non-additive effects in control of the related traits. Having nonsignificant MS(GCA)/MS(SCA) ratio for all traits but 1000-grain weight show higher importance of nonadditive effects in comparison with additive effects of controlling genes. High relative importance of specific combining ability indicated that all traits but 1000-grain weight are highly affected by impacts of specific combining ability. Generally, Dasht, Neda and Binam were the best parents for general combining ability and Binam x IR62871-175-1-10 and Mashhad Domsiah x Binam were the best hybrids for grain yield and its components.

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