Changes of endogenous ABA, GA3 content, ABA/GA3 value in sweet cherry flower buds and effects of correlative environmental factors were investigated during dormancy on 8-year-old ‘Jueze’ (]h4IeMMa)and ‘Zao Hongbaoshi’(Py6Hnoaaa) sweet cherry trees with HPLC (High Performance Liquid Chromatography).It was found that ABA content rose steadily in primary stage and dropped in later stage during dormancy, and its maximum appeared at the begin of November.Contrary to ABA, GA3 content dropped sharply in primary stage of dormancy and rose steadily during release of dormancy, its minimum appeared at the end of November. Moreover, ABA/GA3 value rose with the deepening of dormancy and dropped with the release of dormancy. Temperature affected ABA and GA3 content in dormant flower buds: low temperature(5℃)raised GA3 content and reduced ABA content obviously, moreover, the time when ABA began to fall and GA3 content began to rise advanced after low temperature treatment, which made flower buds release dormancy earlier than contro1. The efect of high temperature(20℃)was contrary to that of low temperature(5℃).Variable temperature(5/20℃)affected dormancy release slightly, but its effect was less remarkable than 5℃ treatment because of the counteract of 20℃. Overshadow treatment before defoliation could reduce GA3 content slightly, but its effect on ABA content was little. The synthesis of GA3 was promoted and synthesis of ABA was inhibited after long photoperiod treatment,contrary to that,short photoperiod treatment raised ABA content and reduced GA3 content sharply.
The innuence of cinnamic acid at diferent concentrations(O,80,150 µmol·L )on leaf gas exchange and cell uhrastructure of cucumber seedlings was investigated in substrate culture. Resulted showed that the einnamie acid at 80 µmol·L significantly reduced the leaf-area,the content of chlorophyll
a,the photosynthesis rate,the respiratory rate,the activity of root and the opening number of stomata,aceompanied by a deformation of the ultrastructures of chloroplast,mitoehondfion.More significa t effects were
observed at a 150 µmol·L cinnamie acid treatment.All these showed that cinnamic acid significantly influenced the photosynthesis by reducing the activity of root,function of the chloroplast and mitoehondrion,stomata
operation.
The strawberry fruits(Fragaria ananassa Duch.‘Chunxing’) harvested at white stage were used to investigate the efects of exogenous ethylene (50 µL·L-1 ) on Ca2+-ATPase activities,O production rate and MDA content of microsomal membrane with or without pretreatment of 100 µmol·L-1 chloropromaize(CPZ),trifluoperizine(TFP)and verapamil(VER),respectively,The results showed that the exogenous ethylene had no obvious influence on O production rate,and had no much effect on MDA content,but stimulated Ca2+-ATPase activitv of microsomal membrane at 12 h after ethylene treatment.Whereas a decreasing of Ca2+-ATPase activities, and relatively higher MDA content were found at 24 h after ethylene removal.The pretreatment of CPZ,TFP and VER reduced the Ca2+-ATPase activities and MDA content of microsomal memb rane under ethylene treatment, but had no significant efect on O production rate.These suggested that cellular Ca2+-CaM may be involved in regulation of Ca2+-ATPase activity and lipid peroxidation of microsomal membrane induced by ethylene.
This paper mainly dealt with the study on shoot organogensis culture in vitro and plant regeneration from sprout explants of Elaeocarpus sylvestris (Lour.)Poir.The results showed that the best media for various stages were as follows:(1) Initial medium:MS+BA 1.0~2.0 mg·L-1 +NAA 0.05 mg·L-1 +3% sucrose;(2)Clump shoot regeneration medium from callus proliferation:MS+BA 1.0mg·L-1 +NAA 0.5mg·L-1 +3%sucrose;Clump shoot regeneration medium from axillary buds:MS+BA 2.0 mg·L-1 +IBA 0.1 mg·L-1 +3%sucrose;(3)Efficiency seedling induction medium:MS+BA 0.5
mg·L-1 +IBA 0.1 mg·L-1 +GA 1.0mg·L-1 +3%sucrose;(4) Rooting medium:1/2 MS+IBA 3.0 mg·L-1 +2%sucrose. In root induction culture.the rate of root formation with membrane filter is higher than that of root form ation with common membrane.
‘Ruipan 3’is a mid—ripening variety flat peach(Prunus persica var.platycarpa Bailey) derived from the cross ‘Okubo ’בChenpu Pantao ’. The fruits are flat,white fleshed,hard melting,sweet,clingstone,and ripen from the end of July to the start of August in Beijing area,about 105 days after bloom.
‘Ninghai Bai’,a new loquat variety.was developed by the systematic selection method from seedling,and characterized by large fruit and white flesh colour. Its fruit shape is long round or round,the single fruit mass 40—65g,the heaviest reaches 86 g. The fruit surface is light yenow white,the skin is thin and aromatic,the flesh iS fine and iuice iS rich,the total soluble solids content iS 13%—16%,the highest reaches 19.2%,the edible is 73.4%, sweet.sour,dense flavour. The ripening date in end of May.high
yield and resistant to freeze.