جستجوی مقالات مرتبط با کلیدواژه "فیلوکرون" در نشریات گروه "زیست شناسی"

In order to study the effects of nitrogen rates and seed inoculation with plant growth promoting rhizobacteria (PGPR) on quantitative and qualitative yield, root characterstics, leaf appearance rate and grain filling period of triticale, a factorial experiment was conducted based on randomized complete block design with three replications in research greenhouse of the faculty of Agriculture, University of Mohaghegh Ardabili in 2011. Factors were: nitrogen rates in four levels (0, 80, 160 and 240 kg N ha-1) as urea and seed inoculation with plant growth promoting rhizobacteria in four levels containing, without inoculation as control, seed inoculation with Azospirillum lipoferum strain OF, Psedomunas putida strains 41, and 9. Means comparison showed that maximum of grain yield (1.36 gr/per plant) was obtained at seed inoculation with Azospirillum lipoferum×160 kg N ha-1. Application of PGPR and increasing of nitrogen rates increased leaf appearance rate. Maximum of phyllochron (5.23 days) and the least of leaf appearance rate (0.191/day) was belonged to treatment compound of N0 × without inoculation seed with PGPR and it was vise versa in treatment compound of N240 × inoculation seed with Azospirillum. Rate and effective grain filling period were affected by nitrogen rates and seed inoculation with PGPR. Maximum of grain weight (0.0516 gr) and effective grain filling period (29.6 day) were obtained in seed inoculation with PGPR×160 kg N ha-1. It seems that in order to increasing of grain yield, leaf appearance rate, grain filling period and some traits be applied 160 kg N ha-1 × seed inoculation with Azospirillum lipoferum

In order to investigate the effects of nitrogen levels on grain yield، phyllochron and leaf emergence rate of maize cultivars، a split plot experiment based on randomized complete block design with three replications was conducted at the Research Farm of Islamic Azad University of Ardabil during 2007 cropping. Factors were: nitrogen levels in main plots (0، 80، 160 and 240 Kg N ha-1) and maize cultivars in three levels (SC-301، DC-370 and SC-404) in sub plots. The results showed that phyllochron، time between the appearance of successive leaves on a shoot، was significantly affected by corn، nitrogen levels and interaction of nitrogen levels × maize cultivars. With increased nitrogen levels، the phyllochron was decreased but rate of leaf appearance was increased. Response of maize cultivars was different to these characteristics. Leaf appearance rate in SC-301 was more than SC-404 and DC-370. The highest leaf appearance rate and the least of time for phyllochron was obtained in treatment compounds of SC-301 with application of 240 kg N/ha. Grain yield was significantly as affected by nitrogen levels، cultivar and interaction of cultivar × nitrogen levels. Maximum grain yield was in SC-404 cultivar and minimum of it was in SC-301 cultivar. Means comparisons showed that maximum grain yield was obtained in SC-404 with application of 240 kg N/ ha. However، no significant different was between application of 160 and 240 kg n/ha. Minimum grain yield belonged to SC-301 without application of nitrogen fertilizer. If growth period was limited، it seems that SC-301 with 240 kg N/ha was applied in order to increasing leaf appearance rate and decreasing of phyllochron. However، if growth period wasn’t limited، it would be better to use of SC-404 with application of 240 kg N/ha.

In order to investigate the effects of seed priming with plant growth promoting rhizobacteria (PGPR) on phyllochron and leaf appearance rate of corn, a factorial experiment based on randomized complete block design with three replications was conducted at the Research Farm of University of Mohaghegh Ardabili in 2008. Factors were: three corn cultivars (SC-404, SC-410 and SC-434) and seed priming with plant growth promoting rhizobacteria in four levels (without priming, seed priming with Azosprilium, seed priming with Azetobacter and seed priming with Azosprilium +Azetobacter). The results showed that phyllochron, time between the appearance of successive leaves on a shoot, was significantly affected by corn cultivar, seed priming with plant growth promoting rhizobacteria and interaction between of seed priming and corn cultivars. Seed priming with Azetobacter decreased the phyllochron but increased rate of leaf appearance. Response of corn cultivars was different to these characteristics. Leaf appearance rate in SC-404 was more than SC-410 and SC-434. The highest leaf appearance rate and the least of time for phyllochron was obtained with seed priming of SC-404 cultivar with Azetobacter. Leaf area index was increased due to seed priming with Azetobacter. In all of priming levels, process of variances leaf area index was similar until 37 days after sowing. From 44-65 days after sowing reached to a maximum level (4.96) and then decreased slowly till 79 days after sowing. This might be related to increasing aging of leaves, shadding and competition between plants for light and other resources. The highest leaf area index obtained in treatment combination of seed priming of SC-404 cultivar with Azetobacter and the least of it was in without priming. Number of leaf per plant and leaf dry matter increased in seed priming with Azetobacter. Thus, it is suggested that in order to increase leaf appearance rate, number of leaf per plant and leaf area index, seeds priming of SC-404 cultivar with Azetobacter be applied in conditions of Ardabil Plain.