Crop Breeding Journal
Volume:1 Issue: 1, Winter-Spring 2011

To evaluate moisture-stress tolerance in reproductive growth stages in five triticale (Alamos83, Lasko, Moreno, Prego, and Zorro), one bread wheat (Roshan) and one durum wheat (Osta-Gata) cultivars, two field experiments were conducted in 2005-06 cropping season at Research Farm, Isfahan University of Technology, Lavarak, Njafabad, Iran. The genotypes were sown in two normal and moisture stress after mid-booting growth stage, conditions-using randomized complete block design with three replications in each moisture regimes. Agro-morphological traits including plant height, spike no. m-2, grain spike-1, grain weight spike-1, 1000 grain weight, grain yield, biological yield and harvest index were measured and recorded. A significant and positive correlation was observed between grain yield and grain weight spike-1 under both conditions. Triticale cultivars performed superior than wheat cultivars under both moisture conditions. Considering the grain yield potential, Alamos 83, Lasko, Moreno, and Zorro cultivars were ranked as the superior group of drought tolerant genotypes. Nevertheless, Moreno was identified as a triticale cultivar that could be grown under both normal and moisture stress conditions with high grain yield.

High molecular weight (HMW) glutenin sub-units and baking quality related traits were studied in 49 Iranian wheat landraces. The protein content ranged from 11.2% to 13.55%, and SDS sedimentation volume varied between 40 and 60 milliliters. High Molecular weight glutenin electrophoresis profiles revealed that at the Glu-A1 locus, the frequency of null allele was higher than sub-units 1 and 2*. Allelic variation for Glu-B1 locus was also considerable as sub-units of 7, 7+8, 6+8, 14+15, 7+9, 17+18, 13+16 and 20 were observed. The highest and lowest frequencies of Glu-B1 belonged to sub-units 7+8 (56%), and 13+16 (2%), respectively. For Glu-D1, 2+12 sub-units (74%) were of higher frequency in comparison with 5+10 sub-units (14%). At this locus, the rare 2***+12' sub-units with frequency of 2% were also observed. Scoring of germplasm based on electrophoresis patterns using Payne method showed that the scores varied from 4 to 8. Based on this scoring, three landraces were ranked as superior. Cluster analysis based on electrophoresis patterns and Jaccard similarity criteria divided the landraces into three groups. Forty landraces with cv. Chamran, as check, were grouped in the first cluster. There was no similarity between grouping pattern based on HMW glutenin sub-units and quality related traits. Considering high variation observed for quality related traits and HMW glutenin sub-units, it can be concluded that these landraces are potential sources of desirable quality traits to be used in bread wheat breeding programs to improve bread- baking quality.

Seed weight (SW) in oilseed rape (Brassica napus L.) is determined during the seed filling period (SFP). A great proportion of variation in SW is associated with environmental conditions in this period. To quantify factors determining SW in open pollinated (OP) and hybrid cultivars of oilseed rape, 12 field experiments were conducted at Agricultural Research Station of Gonbad, Iran, during 2000-07 growing seasons. The experiments were often carried out under optimal growing conditions. Results clearly showed the importance of air temperature in determining the duration of the SFP, and consequently SW. The SW was maximized for the cultivars when exposed to the lower temperatures during the SFP. The ability of cultivars to produce photosynthetic assimilates for developing seeds was an effective determinant factor for SW. The relationships between SW with leaf area index (LAI) and aboveground dry matter, (ADM) at the onset of SFP, was positive and strong, showing a greater response of hybrid cultivars to increase in LAI and ADM as compared to OPs. In both groups, temperature and radiation interactions during SFP, as showed by photo-thermal quotient (PTQ), reasonably explained variation in SW. Therefore, further increase in seed yield (SY) through increasing SW could be obtained by improvement in one or a combination of these environmental factors as well as crop characteristics. These relationships are simple tools that could be applied to simulation models of SW in oilseed rape.

Alfalfa is the best known fodder crop with high ability of biological nitrogen fixation and drought tolerance in dry, Pannonian region of east Austria. Different morphological and physiological characteristics of 18 alfalfa genotypes from different geographical origins, 8 Iranian ecotypes and 10 European cultivars were evaluated under irrigated and rainfed conditions during 2006-08 cropping seasons. The objectives of this study were to measure genetic distance and divergence among genotypes and to classify them based on morphological and physiological characters. Cluster analysis differentiated Iranian ecotypes and European cultivars from each other under irrigated condition, and when data averaged across two environments (irrigated and rainfed). However, under rainfed conditions small changes occurred in grouping of genotypes due mainly to differential responses of the genotypes to rainfed condition. Considerable genetic distance observed between Iranian and European genotypes. Different crossing programs are recommended between Iranian and European genotypes to develop new alfalfa cultivars.

General and specific combining abilities as well as genetic variance components for different agronomic traits in sunflower (Helianthus annuus L.) inbred lines were estimated using “Line × Tester” analysis method. Six new restorer lines were crossed with four CMS lines as tester in 2006 growing season. The 24 F1 single cross combinations were planted in complete randomized block design with four replications in Khoy Field Research Station in 2007 growing season. There were significant differences between hybrids for all traits except for head diameter. Variances among CMS lines for all traits were greater than restorer lines indicating the possible existence of some degrees of maternal effect on some traits, particularly, seed and oil yields. Variances of “Lines × Tester” were not greater than variances for either CMS lines or testers for any traits. This implies the importance of additive effect on concerned traits. Life-cycle duration, 1000 seed weight, seed number head-1 and oil yield were under control of both additive and dominant effects. Seed yield was mainly governed by dominant effects. However, plant height and oil content were controlled by additive effects. Over dominant effects for life-cycle duration and seed yield and complete dominant for plant height were also observed. Principle component analysis (PCA) revealed close positive relationship between seed yield, oil yield and seed number head-1, whereas there were negative association between these traits and 1000 seed weight. Restorer line “R21” and CMS line “CMS356” had stronger effect on their corresponding hybrids. “R23 x CMS78” was identified as superior early maturity hybrid with high oil content and yield.

The objective of this study was to compare non-parametric stability procedures, and to apply different non-parametric tests for genotype × environment interaction (G×E) on seed yield data of 17 chickpea genotypes grown during 2004-05 growing seasons in 10 rainfed environments in Iran. The non-parametric measures used for G × E interaction were highly significant (P<0.01), suggesting differential responses of chickpea genotypes to the test environments. Spearman’s rank correlation was used to measure the relationship between the stability statistics. To understand better relationships among the non-parametric methods, principal component analysis was performed. The results of this analysis and correlation analysis of non-parametric stability statistics and grain yield indicated that only seed yield-stability statistic (Ysi) would be useful for simultaneous selection for high grain yield and stability. According to Ysi statistic, genotype no. 13 was identified as the most stable genotype. It was observed that this non-parametric statistics were associated with high seed yield. Si(1), Si(2), Si(3) and NPi(1) were positively correlated to mean seed yield, however, Si(6), NPi(2), NPi(3) and NPi(4) were negatively correlated to mean seed yield.