جستجوی مقالات مرتبط با کلیدواژه "correlation of traits" در نشریات گروه "زراعت"

The use of local dwarf rootstocks is important due to adaptation with region climate, and prevents entrance of the pests and diseases into the country and economizes procurement and production costs. Hence, in most of the countries, various apple rootstocks have been improved and introduced based on the demand of apple producers and climate conditions. Gami Almasi apple is native of West Azerbaijan province of Iran and adapted to the climatic and soil conditions of that area and has desired traits such as precocious, good compatibility with apple commercial varieties, cold and calcareous soils tolerant and easy reproduction. But due to some of the unpleasant traits; this Apple cultivar cannot be used as a rootstock. Therefore, to identify Suitable rootstocks for apple, the progenies resulting from hybridization of Gami Almasi apple were evaluated for some morphological traits in this investigation.

In order to assess morphological diversity in progenies resulting from free pollination of Gami Almasi apple (59 genotypes) and controlled pollination with MM109 apple as male parent (24 genotypes), variables were included of Leaf area, chlorophyll index, internode length of shoots, tree height, annual vegetative growth, suckers production, iron chlorosis, Burr knots, angel of branches, infection with wooly apple aphids, infection with powdery mildew, infection with pear lace bug and flexibility of branches were investigated. From 89 genotypes evaluated, 24 genotypes were obtained from controlled pollination between Gami Almasi and MM109, and 59 genotypes were obtained from free pollination of Gami Almasi. For evaluation of diversity, Correlations between traits was determined, Cluster was drawn by Ward’s Method, Discriminant and Multivariate Tests were used to determine the appropriate grouping.

Based on the results of correlation analysis, a positive and significant correlation was found between vegetative traits such as height, annual vegetative growth rate, chlorophyll index, internodes length, with branch flexibility. Also, a significant positive correlation between rate of suckers production and Burrknots, and between rate of Burrknots and infection with wooly apple aphids was detected. Cluster analysis using Ward method classified the 89 genotypes into three groups. Groups included: trees with high height, tolerant to diseases and pests, the lowest Burrknots and suckers in group I; trees with medium height, sensitive to diseases and pests, the most Burr knots and suckers in group II; trees with the lowest height, iron chlorosis, Burrknots and suckers, and semi tolerant to diseases and pests in group III.

Trees in group II are not suitable rootstocks for apples, because of undesirable traits such as: production of suckers, highly infected with wooly apple aphids, having Burrknots, iron chlorosis and fragile branches. If the purpose is selecting the rootstocks for resistant to pests and diseases, and needless for scaffolding, trees in group I are appropriate. If the purpose is selecting the dwarfing rootstocks with the lowest suckers and iron chlorosis, semi tolerant to wooly apple aphids, and medium flexibility of branches, trees in group III are appropriate and should be cared.

In order to study the grain yield attributes of sesame in the presence of nutritional treatments and different irrigation regimes, a factorial split-plot experiment was conducted based on randomized complete block design with three replications in Shahed University of Tehran, Iran during 2015-2016. The treatments included irrigation regimes (full irrigation and irrigation up to 65 and 75 BBCH scales), three types of nitrogen fertilizers (nitroxin, urea, and the combination of nitroxin and 50% urea) and four levels of potassium fertilizer (non-fertilized as control, spraying and soil application of potassium nano-chelate and potassium dioxide). The triple interaction effect of irrigation × nitrogen × potassium was significant on plant height, the number of lateral branches, capsules, seeds per capsule, and grain yield. The highest grain yield was obtained from plants irrigated up to 50% of seed ripening (75 BBCH) in the absence of application of potassium and use of nitroxin with an average of 1340.5 kg ha-1 leading to 35% increase, compared to the control treatment. In addition, the grain yield was positively and significantly correlated with stem diameter, plant dry weight, number of capsules and seeds per capsule, and 1000-seed weight. A weak correlation was observed among the morphological traits. Further, there was no significant correlation between morphological and yield attributes. Based on the results of stepwise regression, the maximum grain yield difference was related to the total number of capsules, 1000-seed weight, and number of seeds per capsule, together explaining 98.8% of the grain yield changes.

In this study 22 quantitative and qualitative traits of fruit of 31 Iranian and foreign almond genotypes and cultivars collected in almond collection of Sahand Horticultural Research Station were evaluation. Cluster analysis based on some prominent traits, devided genotypes in to three main clusters. ALC1812, ALC702, ALC206, ALC907 genotypes and Non-Pariel cultivar that were placed in the second cluster, had high kernel percentage and thin shells, so they are suitable for nut trading. ALC1011, ALC1212, ALC123 genotypes and Fragness cultivar that were placed in the third cluster, had great kernels and thick and hard shells like semi-stony nuts, so they are also suitable for nut trading. Results of simple correlation analysis between evaluated traits showed significant positive or negative correlations between some important traits of nut and kernel. Shell hardiness had significant positive correlation with shell thickness and nut weight. Kernel percentage had also significant but negative correlation with shell thickness and hardness but positive correlation with shell opening. Results of this study can be used for selection of promising genotypes and almond improvement programs.

In this study, 11 cotton varieties (G. hirsutum) along with two checks treatments were studied using a randomized complete block design with four replications at Varamin cotton research department to evaluation of correlation between yield and earliness with other quantitative traits in 2008. Agro-morphological and fiber quality of the cultivars were recorded and correlation between yield and earliness with other traits were calculated based on them for each variety. Step wise regression of yield and earliness as independent variables and other traits as dependent variables were calculated separately to each cultivar. The results showed there is a high variation among cultivars regarding correlation between yield and earliness with other traits. The variation also existed among cultivars in term of those traits which entered the multiple regression models as dependent variables. These variations among cultivars are useful in the further breeding programs in view of breaking undesired correlations of the traits and improving them simultaneously in the current cultivars.

In order to determine the effect of weeds on yield and yield components of common bean (Phaseolus vulgaris L.)، this research was carried out as split plot in randomized complete block، with four replications، in Khomein Bean Research Station during 1999 and 2000. There were two plots including naturally contaminated with weeds، and complete weed control. There were also eight subplots containing the following ban cultivars/lines: Dehghan، Daneshkadeh، Naz، Goli، Talash، Mahali Khomein، Sadri and Coc16 bean. Mean comparisons of traits showed that presence of weeds caused loss of 45% in yield، 39% in number of seeds for plant، 5. 1% number of seeds per pod، 36% number of pods in studied cultivars/lines. Goli and Talash with the highest ability of weed competition were superior among studied cultivars. The coefficients of correlation indicated negative and significant correlation of weed dry weight with yield.