This paper describes the embryonic development of the common cutworm Spodoptera litura （Fabricius） （Lepidoptera： Noctuidae） which is divided into eight embryonic stages, through variations in the egg＇s contents....This paper describes the embryonic development of the common cutworm Spodoptera litura （Fabricius） （Lepidoptera： Noctuidae） which is divided into eight embryonic stages, through variations in the egg＇s contents. Experiments were conducted on the eggs ofS. litura under laboratory conditions. The highest concentration of the protein （min.-max.： 32-! 40 lag/egg） and the lowest of the carbohydrate （min.-max.： 3.0-44.0 lag/egg） were obtained; similarly, the DNA content was smaller （min.-max.： 1.0-38.2 lag/egg） than the RNA （min.-max.： 9.2-360.0 lag/egg） throughout the embryogenesis. Three peaks of ecdysteroid titre were observed which were responsible for appearance of particular events during embryogenesis. The last highest peak of 400_＋33.4 lag/egg was appeared at 84 h after oviposition when larva was ready to hatch. Therefore, it is concluded that eight embryonic stages in S. litura were characterized by fluctuation in the egg＇s contents, which were responsible for gradual-progressive embryonic development. The egg-larval development did not show a normal distribution of embryonic developmental-time.展开更多
In order to investigate the likely allelopathic potential of an aqueous extract and powder of Achillea （,4chillea santolina） on the germination and seedling growth of pea （Cicer arietinum）, safflower （Carthamus t...In order to investigate the likely allelopathic potential of an aqueous extract and powder of Achillea （,4chillea santolina） on the germination and seedling growth of pea （Cicer arietinum）, safflower （Carthamus tinctorius L.） and wheat （Triticum sativum）, an experiment was carried out at the laboratory and greenhouse of agriculture faculty of Sho3hid Bahonar University of Kerman, Iran, from October 2009 to March 2010. A completely randomized design with three replicates using five extract concentrations of achillea plant including 0, 25, 50, 75, and 100 g Ll and four amounts of powder of it including 0, 7.5, 15 and 30 g kg1 of soil was employed in laboratory and greenhouse experiments, respectively. All extract concentrations of achillea except 25 g Ll inhibited pea and wheat seed germination significantly, but had no inhibitory effect on the germination of safflower, The powder of mature achillea plants affected the fresh and dry weight and shoots length in these crops negatively compared with the control in all levels. Therefore use of this plant should be prevented in rotation or intercropping with these three crop plants. Further research conducted in the analytical laboratory as well as in the field is needed before a practical application of the extract and powder as weed inhibiting agent can be recommended.展开更多
文摘This paper describes the embryonic development of the common cutworm Spodoptera litura （Fabricius） （Lepidoptera： Noctuidae） which is divided into eight embryonic stages, through variations in the egg＇s contents. Experiments were conducted on the eggs ofS. litura under laboratory conditions. The highest concentration of the protein （min.-max.： 32-! 40 lag/egg） and the lowest of the carbohydrate （min.-max.： 3.0-44.0 lag/egg） were obtained; similarly, the DNA content was smaller （min.-max.： 1.0-38.2 lag/egg） than the RNA （min.-max.： 9.2-360.0 lag/egg） throughout the embryogenesis. Three peaks of ecdysteroid titre were observed which were responsible for appearance of particular events during embryogenesis. The last highest peak of 400_＋33.4 lag/egg was appeared at 84 h after oviposition when larva was ready to hatch. Therefore, it is concluded that eight embryonic stages in S. litura were characterized by fluctuation in the egg＇s contents, which were responsible for gradual-progressive embryonic development. The egg-larval development did not show a normal distribution of embryonic developmental-time.
文摘In order to investigate the likely allelopathic potential of an aqueous extract and powder of Achillea （,4chillea santolina） on the germination and seedling growth of pea （Cicer arietinum）, safflower （Carthamus tinctorius L.） and wheat （Triticum sativum）, an experiment was carried out at the laboratory and greenhouse of agriculture faculty of Sho3hid Bahonar University of Kerman, Iran, from October 2009 to March 2010. A completely randomized design with three replicates using five extract concentrations of achillea plant including 0, 25, 50, 75, and 100 g Ll and four amounts of powder of it including 0, 7.5, 15 and 30 g kg1 of soil was employed in laboratory and greenhouse experiments, respectively. All extract concentrations of achillea except 25 g Ll inhibited pea and wheat seed germination significantly, but had no inhibitory effect on the germination of safflower, The powder of mature achillea plants affected the fresh and dry weight and shoots length in these crops negatively compared with the control in all levels. Therefore use of this plant should be prevented in rotation or intercropping with these three crop plants. Further research conducted in the analytical laboratory as well as in the field is needed before a practical application of the extract and powder as weed inhibiting agent can be recommended.
