JOURNAL OF CROP PRODUCTION RESEARCH (ENVIRONMENTAL STRESSES IN PLANT SCIENCES)
Year:2012 | Volume:4 | Issue:2|Papers Count:8

Bread wheat relatives are valuable sources for tolerance to biotic and abiotic stresses. In order to identify heat tolerant accessions in wheat collection of National Plant Gene Bank of Iran, 512 wheat accessions were evaluated in Ahwaz, Iran. The accessions were planted in two separate experiments of heat stress and non-stress in augmented design. Heat stress was induced by late sowing. Fourty-six accessions out of the total wheat relative species survived comprising 32 accessions of T. turgidum ssp. durum, eight accessions of T. turgidum ssp. turgidum, five accessions of T. compactum and one accession of T. dicoccum. Some important agronomic and phonological traits were measured. The amount of stress intensity was evaluated 0.71. The largest grain yield of five spikes in non-stress condition (Yp) and in heat stress condition belonged to accessions 40 and 9 (both durum), respectively. The accession 34 (durum) had the largest amount for MP, GMP and STI. STI and GMP, among the studied stress tolerance indices had acceptable correlation with Yp and Ys and were identified as suitable indices. The impact of the evaluated traits on STI and GMP was investigated by stepwise regression. The traits entered in regression model were the same for both STI and GMP comprising number of grains per spike in stress and non-stress conditions, 100-grain weight in stress and non-stress conditions and stem diameter in stress condition. The trait 100 grain weight in both regression models of STI and GMP had the largest coefficient indicating its importance. The accessions were distributed in 3D plot of Yp, Ys and STI. Twelve accessions were located in A region (higher Yp and Ys) including accessions 2 (diccoccum) 6, 9, 15, 21, 34, 40 and 42 (durum), 22, 28 (durum), and 3 and 5 (compactum) and were identified as the most heat tolerant ones.

In order to evaluate the planting date on yield and yield components of three soybean cultivars as second planting in the summer of 2009 an experiment was conducted in research Agro meteorology farm in Khorramabad in factorial randomized complete block design with three replications. Soybean cultivars used (M7, M9, and LODA) and sowing date treatments, included 21 June, 30 June & 10 July. The results showed that planting date on the number of seed per plant, pod weight, TSW, seed yield, protein, oil yield and protein yield in the 1% probability level was significant. In addition, for number of pods per plant, oil percent and Harvest index had no significant effect. By planting on 21 June the traits such as total number of pods per plant, seeds per plant and yield had the highest amount while the third planting date (10th July) had the highest seed weight, but other traits showed significant reductions. The test results indicate that LODA variety in 21 June date is proper cultivar of soybean in Khorramabad and in delay planting treatment, M7 varieties should be used.

In order to identify drought tolerance barley genotypes, screen quantitative indices drought tolerance and appointment best indices, one experiment carried out with 20 barley genotype. This experiment excuted in RCBD with three replications under full irrigation and drought stress conditions during 2009-2010, cropping season in broujerd agricultural research station. In order to evaluation of barley genotype for drought stress, stress susceptibility index (SSI), stress tolerance index (STI), geometric mean productively (GMP), tolerance index (TOL), mean productivity and harmonic mean (HM), data were collected. The result indicated significant different among all genotypes with respect to all quantitative indices and yield performance in both environments. This show the possibility of selection for drought tolerance among genotypes, and involvement of superior ones inbreeding programs. The result of experiment showed that No.7 (MB-79-4) genotype in the irrigation condition and NO.14 (MB-82-4) in dry condition has the highest grain yield. Highest HM, GMP, MP and STI were obtained in the No. 11 and 14 (CB-83-15 and MB-82-4) genotypes. Evaluation of genotypes for stress TOL and SSI index showed that No. 6 (CB-83-17) genotype has high index. Correlation analysis between yield and all indices revealed that MP, GMP, HM and STI are all indices for screening of drought tolerance genotypes. Accordingly, genotypes No. 7, 11, 14 and 19 (MB-79-4, CB-83-15, MB-82-4 and MB-79-15) were selected as drought tolerance genotypes. Biplot multivariate technique located the genotype No. 7, 11, 14 and 19 (MB-79-4, CB-83-15, MB-82-4 and CB-84-10) near the vectors related to drought resistance indices.

To comparison of quality and quantity characteristics of improved and local cultivars of cot-ton an experiment was conducted using based on randomized complete block design with four replications at Agricultural and Natural Resources Reasearch Center of Yazd in 2009 cropping season. Experimental treatments included three improved cultivars (Mehr, Varamin, Sindoz) and local cuitivar as control. Each plot consisted of six lines with six meters and with 50 Cm between the plots. Different traits including plant height, different harvest yield, the total fiber of seed and lint percent were measured and then quality traits of each experimental were evaluated. The results showed the significant difference between cultivars concerning quantitative and qualitative traits and improved cultivars were earlier than local cultivar but their yield was the same. Lint percent of local cultivar was lower than improved cultivars. Generally, sindoz cultivar produced the highest (4079 kg/ha) seed cotton yield and lint percent (37.48) and introduced as the best cultivar.

Effect of water stress and absorbent substance such as animal manure, zeolite and bentonite in field trial training was conducted in Islamic Azad University in agricultural research during 1389-90. The experiment was as split plot in the basis of completely randomized blocks design with three replications. The experiment consisted of three irrigation treatments (100%, 85% and 70%) required water treatment in the main plot, Use absorbent materials on six levels (Controls, 30 tons of manureper hectare, 15 tons of manure and 4 tons zeolite per hectare, 15 tons of manure per hectare consumption and two tons of bentonite, 4 tons per hectare zeolite and consumption of two tons bentonite per hectare and 15 tons of manure, 2 tons bentonite and 4 tons of zeolite per hectare) in sub plots on wheat cultivar alvand. The results showed that the effect of water stress on traits of rate of water loss (RWL), Leaf extremity water, initial water content (IWC), Biomass and grain yield clusters of clusters in a level and water saturation deficit (WSD) were significant at the five percent level. The Yield rate of water loss (RWL), initial water content (IWC), Water saturation deficit (WSD) were significant at one percent. Zeolite consumption 4 tons and 15 tons of manure per hectare can increase the water content and biomass yield clusters.

Seed priming in the delay cropping chances of Silage Corn (S.C704) establishment and plant density is higher and duo to increase yield. In order to investigate the effect of seed priming, plant density and delay planting effects on emergency rate and forage dry yield of corn an experiment was carried out as split-split plot based on completely randomized blocks design in four replications in Mazandaran AgricultureResearch Center, Qaemshahr, Iran in 2010. The experiment factors including; Delayed sowing dates were at two levels (27 July and 13 August) as the main factor, and plant density in two levels (70000 and 90000 plants per hectare) as sub factor and the sub-sub factor in four levels of seedpriming including: No seed priming (Control), pure water, PEG concentration 8% and KNO3concentration 0.5%. Dry forage yield and speed emergence with delay in planting from 27 July to 13 August 26.7 and 9.6% had decreased, respectively. Maximum of plant dry weight, ear dry weight to total, leaf dry weight to total and minimum of stem dry weight to total for planting dates observed on 27 July. Dry forage yield and emergence speed with increasing plant density from 70000 to 90000 plants per hectare were increased 21.1% and 24.6%, respectively. Seed priming with KNO3 conducted to maximum stem dry weight to total. The highest dry forage yield with 12478 kg/ha and emergence percentage with 91.5 % was obtained for 90000 plants per hectare and 27 July planting time. Triple interaction effects on none of traits were no significant.

Due to study the Effect of lead, azospirillum and humic acid on chlorophyll content, root and shoot dry weight in rapeseed (Brassica napus L .) an experiment was done as factorial in the basis of complety randomized design in 4 replication during 2011 at Islamic Azad university shahr-e-Rey branch. Experimental factors contains: Lead heavy metal in 3 levels (0, 250, 500 and 750 mg/Kg of soil), Azospirillum bacteria inoculation in 2 levels (0 and application) and humic acid in 2 levels (0 and 8 g/ha application). The results indicated that all factors simple effects was significant and interaction effects did not showed any significant difference. Mean comparison single effects indicated that 750 mg/kg lead application decreased chlorophyll content, root and shoot dry weight to 0.94 mg/g, 3.68 g/plant and 13.12 g/plant alternatively. In this case after Azospirillum application root and shoot root dry weight increased 10% and 6.5% consequently. The humic acid consumption increased Chl a (0.75 mg/l), Chl b (0.39 mg/l) and Chl a+b (1.12).

In order to study the effects of end season drought stress on yield, yield components and some morphological characteristics of 7 varieties and promising lines and assessment based on drought indices, two separate experiments in randomized complete block design in three replications conducted in the agriculture research centre of Birjand. Drought condition made in the first experiment after anthesis and irrigation was conducted as usual in the second experiment. Varieties including Nosrat, Fajre-30 and Yousef and promising lines including MB-86-17, MB-86-10, MB-86-6 and MB-86-5 were cultured at two conditions. The results of combined analysis showed that drought stress has a significant effect on all characteristics except of number of seed per spike. Based on means comparison, highest seed yield with means of 8.26 ton/ha achieved from normal irrigation and lowest with means of 4.58 ton/ha achieved from drought stress condition. Also the results showed that lowest seed yield with mean of 5.3 ton/ha were related to Nosrat variety and highest seed yield with mean of 6.8 ton/ha were related to the Fajre-30 line, and there was no significant difference between these lines in context of seed yield. Yield in drought stress condition has a positive and significant correlation with HARM, MP, GMP and STI indices. Also, Fajre-30 variety and MB-86-10 and MB-86-17 lines recognized as the most tolerant lines to end season drought stress based on different indices.