Population means and correlation analyses of growth parameters in lisianthus (Eustoma grandiflorum Shinn.)

Summary The variation in growth characteristics among lisianthus (Eustoma grandiflorum Shinn.) genotypes was investigated. The genetic control of several growth parameters was studied by analysing parental, F1, BC1 and F2 populations. The parameters analysed were stem elongation rate (SE), stem diameter (SD), leaf width (LW), number of nodes (NN), node length (NL) and days to flowering (DF). The genotypes tested exhibited great variation for all parameters. A particularly wide variation was noted for SE, ranging from 3 to 56 mm/week. This variation was partially attributed to a differential sensitivity to rosette formation. There was a marked positive heterosis for SE, SD, LW and NN; these parameters proved to be genetically correlated within segregating populations. DF was slightly negatively correlated with SE, NN and NL. It was concluded that SE and DF were independently controlled.Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel. No. 1196-E, 1993 series.     

Structure and variation of subterranean clover populations from Sicily,Italy

Summary A collection of subterranean clover lines singled out from populations of the species Trifolium brachycalycinum and T. subterraneum collected in Sicily, Italy, was examined at two localities for flowering time and at one locality for oestrogen content and seed yield. The structure and variation of the populations of the two species were compared. The relationship between flowering time of the populations and some environmental features of their collection sites was examined to assess whether the maturity requirements of the two species were similar and to frame selection models focused on developing varieties of appropriate maturity. Populations of T. subterraneum were, on average, more complex than those of T. brachycalycinum, being characterized by higher number of lines per population and greater intra-population variation for flowering time, oestrogen content and seed yield. Furthermore, populations of T. subterraneum were, on average, about 15 days earlier than sympatric populations of T. brachycalycinum. Both the greater variation and the relative earliness of T. subterraneum occurred irrespective of the environments of origin of the populations. Inferences are drawn on the adaptive advantages that such features confer to T. subterraneum. Mean flowering time of the populations increased on increasing annual rainfall and altitude of the collection sites. However, the changes in maturity appeared almost exclusively related to variations in rainfall in T. subterraneum, while in T. brachycalycinum the effect of altitude was greater and that of rainfall less marked than in the former species.     

外源GA_3对白桦成花基因影响的定量PCR分析

植物开花是高等植物由营养生长向生殖生长转变的重要生理过程,是个体发育和后代繁衍的中心环节。赤霉素是调节植物生长发育的五大激素之一(Takahashi et al.,1991),赤霉素处理也是人工调控植物成花的最有效途径之一,因而成为近年来成花     

迎春·连翘切枝冷藏开花效果比较研究

[目的]控制连翘、迎春的花期,满足晚春木本切花需求。[方法]选取枝条至少在10个花蕾以上的迎春、连翘当年生枝做切枝(20～25cm长)和冷藏(0～2℃)处理,通过低温冷藏延迟迎春和连翘的花期,研究迎春、连翘切枝冷藏延迟开花的技术措施,提高开花质量和效果。[结果]经过冷藏处理,迎春、连翘切枝的开花期延迟了1个月,迎春冷藏1～30d效果比较好,连翘冷藏1～20d效果比较好。迎春花期持续时间长,而连翘开花时间集中。冷藏后的花期曲线大都呈单峰曲线状态。冷藏5～25d的开花效果比较好。[结论]连翘、迎春含苞枝条在0～2℃冷藏5～25d后可以正常开放。     

灯照控制菊花花期的问题

在生产栽培工作中,针对旧式的灯照控花方式存在的弊端,从理论上分析其科学的含量,着意从多方面去改善和革新现有的灯照控花方法,致力于提高菊花的花期控制技术.     

光照处理对晚花波斯菊观赏性的影响

[目的]探讨光照处理对晚花波斯菊开花及观赏性的影响。[方法]采用随机区组设计。每天光照时间设81、01、2 h 3个水平,光照天数设7、142、1 d 3个水平,自然光照处理为对照,研究光照处理对晚花波斯菊观赏性的影响。[结果]波斯菊的观赏性以株高50 cm左右,分枝适中,株冠均匀丰满,植株开花数较多,花朵大为好。光照处理能显著影响晚花波斯菊的开花时间和观赏性状。光照天数和每天光照时间之间存在互作。光照时间处理中,以10 h光照处理植株开花最早,单株开花数最多。随着光照处理天数的增加,从播种到现蕾、开花的时间逐渐缩短。光照天数处理中,以每天处理10 h,处理21 d最好。[结论]处理14 d,每天10 h光照时,晚花型波斯菊的观赏性最好。     

角倍蚜虫夏寄生盐肤木物候期的观察研究

角倍蚜虫夏寄主盐肤木物候期观察研究结果表明：坡向对物候期影响较大，不同坡向盐肤木的萌芽、展叶、开花、结实、落叶等物候现象存在一定程度的差异，出现最早的是南坡，最迟的基本上是北坡．福建南平适宜引种放养角倍蚜虫的展叶期是３月下旬至４月上旬；展叶早、速度快、历期短的是南坡，历期仅１０天，于３月底结束；历期较长的是东坡，约２０天，展叶盛期可持续到４月上旬；放养排序为：南坡＞山凹＞西坡＞北坡＞东坡．     

蔸龄对苎麻光周期钝感生理雌性系生长,成花及性别表现的效应

对光周期钝感生理雌性系ＮＧ１ １、２、３年生麻的观察结果表明：随蔸龄的增大，株高增加、叶片数增多；第１期花的雄花及总花序数也随之增加；二麻的总花序节数及雄花序节数大大高于头麻，不同年份的成花量及性别比有较大差异。蔸龄及温度对ＮＧ１的生长、成花及性型表现有重要作用。