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1.
通过对油松小孢子叶球性反转现象的观察,结果表明:已经完成分化的正常小孢子叶球发生了性反转,从其顶端的小孢子叶开始向基部逐渐转变成大孢子叶,直至整个小孢子叶球转变成异常的大孢子叶球;异常大孢子叶球具有接受花粉的能力,并在枝条上发育成为蔟状着生的小球果。  相似文献   

2.
以烟台市栽培的绿化树黑松为材料,观察正常和异常幼果与近成熟球果着生状态,并对异常球果发生原因进行分析,结果表明:在原本属于小孢子叶球着生的当年生枝条基部着生着异常幼果(最多者为11枚)和近成熟异常球果(最多者为12枚),它们由小孢子叶球发生性反转途径转变为异常大孢子叶球进而发育为异常球果(不规则上下排列)。黑松正常幼果(球果)由大孢子叶球发育而来,着生在当年生枝条顶芽周围,呈环周式不等距同心圆水平排列;长椭圆形,中下部鳞脐平滑,上部略有凸起;一个枝条着生1~7枚不等,以4~5枚为主,稀1枚和7枚;与油松幼果有本质性遗传差异。  相似文献   

3.
马尾松雌、雄球花的形态发育   总被引:1,自引:1,他引:1       下载免费PDF全文
本文报道了马尾松雌、雄球花的形态变化与发育进程。①雄球花(即小孢子叶球):雄球花芽聚生于当年春梢基部,外被芽鳞,芽鳞张开球花显露。小孢子囊由表皮、中间层、绒毡层和造孢组织组成。绒毡层细胞是双核的。小孢子四分体为四面体形和对称形。单核花粉时期花粉外壁延伸成2个大小相同的气囊;成熟花粉具2个原叶细胞、1个生殖细胞和1个管细胞。②雌球花(即大孢子叶球):雌球花芽着生于当年春梢顶端,顶部芽鳞张开后雌球花显露。珠鳞以螺旋状排列在球花中轴上,腹面着生两枚倒生胚珠。胚珠由珠被和珠心组成,单珠被,受粉时珠鳞张开;珠心内含1或2个大孢子母细胞。雌球花各发育阶段的出现时间,均较雄球花迟。  相似文献   

4.
以四川杉木种子园母株为试验材料,观察春季雄球花和小孢子叶球外部形态发育与小孢子发育的对应关系,结果表明,同一个小孢子叶球上的小孢子叶发育基本同步;小孢子叶的颜色和长度与小孢子发育极其相关,小孢子叶球整体呈青色、长5 mm时,其内部小孢子基本处于四分体时期;当小孢子叶之间的鳞片失水变黄、小孢子囊壁变为淡黄色时,其内部小孢子基本处于单核靠边期,采集小孢子叶球为此状态的雄球花,在干燥温室中放置12~24 h后,能收获大量成熟的、活力旺盛的花粉。  相似文献   

5.
10~15年生结果的火炬松(Pinus taeda)雌孢子叶球的发育,一般要经过二年(越过二个冬天)才能成熟。试验结果表明,雌孢子叶球芽当发育形成原始体之后,必须经过秋冬低温时期,进行生理休眠。越冬后,随着气温的上升,逐步发育成为一年生孢子叶球。这些一年生孢子叶球再经过第二次秋冬低温休眠期,最后在翌年秋季成熟。这两次低温休眠期对于雌孢子叶球的发育是必不可少的。而雄孢子叶球和营养芽在发育过程中,虽然也有类似的休眠现象,但在生理上却不一定是必不可少的,它可以通过人为措施来打破。 材料和方法 在阿肯什州中部火炬松种子园中(无性系WMAPT—1)采取带有花芽(雌、雄孢子叶球芽,一年生孢子叶球)或营养芽的接穗,嫁接到盆栽的二年生火炬松苗上。  相似文献   

6.
杜松小孢子的发生和雄配子体的发育   总被引:1,自引:0,他引:1  
利用常规石蜡制片技术,对杜松小孢子发生及雄配子体的发育过程进行观察.杜松的雄球花3月初开始分化.小孢子囊壁一般包括3层细胞:表皮、中层和绒毡层.造孢细胞在3月中旬形成,3月下旬形成小孢子母细胞,4月上旬开始减数分裂,4月中旬形成四分体,4月下旬小孢子从四分体释放出来.5月上旬开始散粉,成熟花粉粒为单核花粉粒.散粉后,胚珠内的花粉萌发出一短的花粉管后休眠,第2年4月份开始分裂形成管细胞、不育细胞和2个精子细胞.小孢子母细胞发育表现出不同步现象,部分小孢子母细胞在发育过程中退化,在小孢子囊内形成空腔.小孢子囊在小孢子叶基部远轴面和叶腋处都有发生,小孢子叶球为复合小孢子叶球.  相似文献   

7.
本文从形态学和解剖学两个角度对松属植物大、小孢子叶球发生、发育的特点以及大、小孢子叶球发育过程中存在的几种特殊现象进行综述,系统地总结了大、小孢子叶球发生部位、发生时间、分化阶段特征以及小孢子叶球中花粉的发育、大孢子叶球发育中颈卵器的形成等多个重点阶段,提出了继续开展相关研究的方向。  相似文献   

8.
本文对东北红豆杉雌、雄球花及果实发育形态建成和生殖物候进行观察,结果表明:花芽形成于上一年7—9月,雌球花在树冠上的分布较均匀,雄球花绝大多数分布于树冠的中下部,雌、雄球花多着生在树冠外部枝条叶腋处。4月中旬珠柄伸长,胚珠外露,胚珠珠孔液滴出现,小孢子叶球伸出、散粉。4月下旬至5月初胚珠珠孔液滴和小孢子叶球散粉出现盛期和末期。珠孔接受花粉最佳时期与散粉期均为7~10 d,雌、雄植株花期同步性较高。授精后,子房开始膨大生长,7、8月份为果实膨大期,9月上旬,假种皮初熟。9月中旬至下旬,果实直径最大。9月中旬至10月下旬假种皮陆续成熟、干枯。10月上旬至11月上旬果实陆续成熟、脱落。  相似文献   

9.
1978年我们在浙江省首次发现杉木(Cunnighamia lanceolata)雄性不育株。本文对杉木雄性不育株的小孢子叶球进行了有关形态学和生理生化方面的初步研究。结果表明:杉木的雄性不育属于无孢子型。造成雄性不育的直接原因是绒毡层的过早解体和小孢子母细胞不能完成减数分裂。雄性不育株的雌球花发育正常,并能正常开花、授粉和结籽。在小孢子发生和发育过程中,不育株小孢子叶球的呼吸强度明显低于可育株的小孢子叶球,并表现出一定的规律性。不育株与可育株之间过氧化物酶同工酶谱具有明显差异,前者的酶带数始终多于后者。作者认为,杉木不育株中可能存在雄性不育细胞质基因,通过影响或调节编码过氧化物酶的核基因的表达,或影响核基因遗传功能的正常发挥,引起核质之间的不协调而导致雄性不育。  相似文献   

10.
以城市庭院绿地栽培的樟子松为材料,观察分析球花发育和传粉等开花生物学特性,结果表明:在2013年的气候条件下,群体花期持续10 d,单株传粉变动于5~8 d之间,平均为6.2 d。在不同植株中,雄球花花序大小和着生的小孢子叶球数量有明显的差别,1、2、3号树的雄花序平均长度和平均着生小孢子叶球数量分别为3.2 cm和68枚、2.8 cm和52枚、2.4 cm和44枚。小孢子叶球膨大显露、花粉母细胞减数分裂、群体撒粉初期、群体撒粉结束期4个阶段≥10℃有效积温分别为68℃、141℃、278℃和367℃。  相似文献   

11.
华北落叶松传粉生物学的研究   总被引:7,自引:1,他引:7  
本文研究了华北落叶松雌雄球花在树冠上的分布和树冠周围花粉密度变化规律、传粉机制、胚珠接收花粉量及结实状况等。雌球花主要分布在树冠中上部2-4龄枝上,雄球花分布范围较广,且常与雌球花混生;树冠周围花粉密度与雄球花的分布密切相关,中部最大,依次向上下两端减少。依据雌球花形态特征的变化,可将传粉期为5个阶段,整个期间无传粉滴出现,由球被顶端大裂片的珠被毛接收花粉。最佳传粉期约为2天。胚珠平均接收4粒花粉,虽然胚珠接收的花粉数与饱满种子的产量有一定的关系,但并不是造成空粒的主要原因。此外,讨论了不同授粉方式对种子产量的重要意义。  相似文献   

12.
英德火炬松改良种子园无性系开花的时空变化   总被引:1,自引:1,他引:1  
对英德火炬松改良种子园建园无性系的开花习性进行了观察,发现大部分无性系雌、雄花发育良好。无性系开花时间大约在3月4~26日,大多数无性系雌花在3月7—8日开始开放,少数在3月4~6日开始开放,雄花大多数在3月9~10日开始开放。总体上雌花比雄花早2~3d开放,早1~2d结束。全园雌花盛花期为3月8~17日,雄花盛花期为3月12~19日,雌、雄花盛花期有一个星期的时间相遇,自然条件下可保证充分授粉。种子园嫁接后第2年到第3年,90%以上的无性系开花,平均开花株率略高于70%;从第3年到第4年,100%的无性系开花,开花株率接近95%。说明嫁接后第3~4年,是种子园进入盛产的关键时期,也是实施人工控制授粉的有利时期。  相似文献   

13.
Anatomic Study of Female Sterility of Pinus tabulaeformis Carr.   总被引:3,自引:0,他引:3  
The anatomic research on the mutant clone of Pinus tabulaeformis Carr.in the seed orchard in Xingcheng,Liaoning Provinces was carried out.The female cone of the mutant clone looked like normal,but its ovules degenerated in early stage.This paper trics to find out the reason and time of ovule abortion.It seems that the ovule abortion is probably caused by female sterility because the microspores of this mutant clone were normal.Through the serial observations on the one-year-old macrosporangiates and the ovules of two-year-old female cones of mutant and normal clone,it is found that the reason of ovule abortion in mutant clone is the failure of the mitosis of free nuclei in the female gametophyte,and the time is about in the early April.  相似文献   

14.
马尾松种子产量预测方法初步研究   总被引:2,自引:0,他引:2  
马尾松种子产量预测方法初步研究周志翔(华中农业大学林学系武汉430070)宋丛文(湖北省林木种苗管理站武汉430070)冯春莲(湖北省林业技工学校武汉430065)关键词马尾松,种子产量,预测模型林木种子产量的预测预报是有计划地开展种子经营管理和科...  相似文献   

15.
马尾松球果发育和元素含量的季节动态张云跃,李佩瑜,简梦完(湖南省安化县林业科学研究所安化413500)关键词马尾松,球果发育,元素含量,季节变化马尾松(N。。s。at。on7a。aLamb.)为我国亚热带广泛分布的树种,适应性强,传统上一以供应薪材为...  相似文献   

16.
杉木种子园种子产量预测预报模型研究   总被引:6,自引:0,他引:6  
林木种子是林业生产的物质基础,种子产量的预测预报是实现林木种子生产科学管理的重要基础性工作。随着预测超前性、简便实用性和精度要求的不断提高,多种预测方法便应运而生(方升佐,1990;陈幼生,1993)[1,2]。笔者结合杉木[Cunninghamia...  相似文献   

17.
Large numbers of cones (strobili) were induced in a 10-year-old plot of mature grafts of Picea sitchensis (Bong.) Carr. All trees injected with 20 mg GA(4 + 7) in June initiated female and male cones in the same year. This treatment increased the number of female cones per plant 12-fold above the controls, more than doubling the percentage of cones that were female. Complete bark-ringing (done in May of the previous year) showed an additive effect with GA on the number of female cones formed, but a negative interaction on the number of male cones induced. Ringing promoted male cone production most when used alone. Treatments, singly or combined, also increased the proportion of cones that were lateral, compared with the preponderance of terminal male cones in the controls. The effects were apparently not directly associated with alterations in vegetative vigor, although these occurred causing a reduction in the proportion of buds containing vegetative shoots the following year. The clones differed in most characteristics, but both sparse and prolific clones were induced to reproductive activity. Viable seed yields per tree, and notional production from seed-orchards were enhanced almost 10-fold by GA injection, and about 4-fold by bark-ringing and GA + bark-ringing.  相似文献   

18.
Apparently healthy and C. conigenum infected female strobili of Pinus maximinoi, collected in Guatemala, were histopathologically studied by light microscopy. Scales from infected cones were fused and fertile scales had aborted seeds. Infected cone scales lacked fibre cells in the cortex, which are abundant in healthy cone scales. Intercellular spaces of cortex contained abundant hyphae compared to phloem and xylem. The cell walls of infected tissues in the ovules were darkly stained, while those of comparable healthy tissue were colourless under Pianeze's IIIB stain. Infected ovules of different developmental stages with nucellus, or nucellus plus spongy tissue, were observed. The cells of each tissue type contained many haustoria and did not develop into female gametophyte and embryo. Ovule colonization by hyphae appeared after pollination and subsequently caused their early abortion.  相似文献   

19.
福建山樱花种子发育观察与育苗技术研究   总被引:6,自引:2,他引:4  
对福建山樱花花期、种子发育过程进行多年的定点不定期观察,开展了福建山樱花种子的不同催芽条件和不同播种方法的育苗试验。研究结果表明:在福建省南平市,福建山樱花4月20日左右胚珠发育成熟,采种期为4月25日左右;冷藏至翌年春播种,种子发芽率达96.8%;撒播芽苗移栽的播种方法最好,1年生苗木平均高1.72 m、平均地径1.03 cm;福建山樱花生长较迅速,3年生平均高可达3.6 m、平均地径可达3.8 cm。  相似文献   

20.
Abstract

Female fertility is the basis for the output of seeds from clonal orchards and its variation is of major interest for the economics and biology of seed orchards, especially for the efficiency and diversity of seed orchard crops. Assessments of female fertility variation in 10 mature (>15 years old) seed orchards of Scots pine (Pinus sylvestris L.) were evaluated and compared. Depending on the individual orchard, fertility variation for each clone was assessed in slightly different ways, e.g. number of strobili, cones, seeds or litre of cones per ramet. Assessments in five of the orchards were made over consecutive years. The main result was that the clonal variation in mean female fertility per surviving ramet was lower than expected from the literature; the Kang–Lindgren sibling coefficient (Ψ) within individual years averaged 1.35. The variation between ramets within clones and years was of similar magnitude as that between clones. Clone by year interactions were noticeable, but were slightly lower than the variation between as well as that within clones in individual years. There was considerable variation in the variance components between years. The limited variation in female fertility indicated that it should not be a selection criterion when selecting clones for a seed orchard. Furthermore, it will not result in large differences between clones in seed set or large reductions in gene diversity in productive Scots pine seed orchards.  相似文献   

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