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1.
巴西橡胶树大孢子发生和胚囊发育过程的研究   总被引:3,自引:2,他引:3  
用石蜡连续切片,观察巴西橡胶树胚珠和大孢子发生、胚囊发育过程,结果如下:1.倒生胚珠,胚珠原基在雌蕊心皮来完全愈合成完整子房前产生。珠被发生于造孢细胞末期或大孢子母细胞早期。至二核胚囊期,两层珠被顶部合拢包围珠心。2.具厚珠心,其顶部形成珠心喙;在珠孔上方有珠孔塞,它起源于胚珠附近的胎座组织。2.胚囊发育属于蓼型。发育过程一些明显的变化是:(1)细胞逐渐液泡化;(2)从单核胚囊开始,细胞核连续三次分裂、分化、定位和产生新壁形成七细胞胚囊;(3)出现极性,极性的表现在大孢子母细胞期就开始。4.一些品系的两性花中,雌、雄生殖细胞问各发育阶段有明显的对应关系。  相似文献   

2.
栽培大豆、半野生大豆、野生大豆比较胚胎学研究   总被引:3,自引:0,他引:3  
通过对栽培大豆、半野生大豆和野生大豆比较胚胎学研究,指出了三种类型大豆具有相同的胚胎学发育特征,这些特征如下:1.雄性孢原为表皮下多细胞;小孢子母细胞减数分裂的胞质分裂为同时型;四分孢子主要为正四面体形,少数为左右对称形;成熟花粉粒为二细胞型;花药壁的发育属基本型;绒毡层细胞单核,属分泌型绒毡层。2.单室子房;弯生胚珠,双珠被,厚珠心;胚珠亚表皮下多孢原;多数大孢子四分体线形排列;少数为“T”字形排列,合点端大孢子有功能;胚囊发育为蓼型,反足细胞短命。3.大孢子发生较小孢子发生稍晚,但发育速度较快,后期雌、雄配子体同步成熟。4.自花授粉;受精过程属有丝分裂前配子融合类型。5.胚的发育属柳叶菜型;核型胚乳,胚乳发育中后期胚囊合点端存在胚乳吸器;胚珠合点端具承珠盘结构。  相似文献   

3.
巴西橡胶树胚及胚乳发育的研究   总被引:2,自引:2,他引:2  
本文分三方面叙述。 1.雌蕊及胚珠的构造:巴西橡胶花的雌蕊由三心皮构成。花柱中的诱导组织明显。子房三室,每室仅有一枚倒生胚珠。珠孔上方罩有一帽状珠孔塞。珠心发达,属厚珠心型,有明显的珠心喙。胚囊由8个细胞组成。 2.胚乳的发育、消退和外胚乳的形成过程:初生胚乳核在授粉后24小时开始进行第一次有丝分裂,授粉后60—65天珠孔端的游离核开始产生细胞壁,到授粉后70天左右,全部的游离核都形成了胚乳细胞。以后胚乳细胞的养分逐渐被发育中的幼胚和珠心所吸收,最后只剩下极薄的一层。而珠心组织则一天天增厚,其细胞体积也一天天增大,最后成为种子的永久性的营业养组织即外胚乳。 3.胚的发育过程:合子横分裂是在授粉后40天左右。接着顶细胞进行纵裂,随后胚体细胞以对角线的方式进行分裂产生一个具胚芽原的幼胚。随着顶细胞的发育,基细胞也进行横分裂产生上下两个细胞,上方一个体积略为增大而形成胚柄;下方一个将来发育成根冠。因此巴西橡胶树的胚属十字花型。  相似文献   

4.
荔枝大孢子发生和雌配子体发育的研究   总被引:4,自引:2,他引:4  
本研究对荔枝大孢子发生和雌配子体的发育,及其淀粉的动态和引起座果率低的原因,作了较详细的观察,结果如下: (1) 子房两室,每室具一个胚珠。 (2) 倒生胚珠,具两层珠被。 (3) 胚珠发育属厚珠心胚珠。 (4) 胚囊发育为蓼型。开花前,大多数情况下,两个极核均合并为次生核。成熟胚囊包含卵器(由两个助细胞、一个卵细胞组成),中央细胞及三个反足细胞。 (5) 从孢原细胞分化,雌配子体发育成熟至开花,约需19~21天。 (6) 胚珠早期退化是导致座果率低的原因之一。 (7) 大孢子发生和雌配子体发育过程中,胚珠内淀粉的积累是由珠心顶端到胚珠基部,由外珠被到内珠被。胚囊内淀粉主要分布在次生核的周围以及它和卵细胞之间的细胞质中。开花前一天的花柱中已积累大量淀粉粒。  相似文献   

5.
从解剖学、细胞生物学及遗传学角度对海南油茶不育株花器发育过程导致不育的原因进行研究。以海南油茶正常株和不育株为实验材料,对其花芽发育过程外部形态特性进行阶段性比较观察,并应用花粉原位萌发技术检测其花粉萌发及花粉管发育差异;应用石蜡切片法对花芽分化过程中雌雄蕊进行解剖学观察,分析雌雄蕊发育时期与其花芽外部形态的相关性。结果表明:不育花与正常花外部形态上并无明显差异,但不育株开花后子房即脱落,表明没有正常授精,不育株柱头授粉后花粉粒不萌发,花粉管并不伸长;从雌雄蕊石蜡切片可以看出,不育株花器发育失常,其花药的绒毡层降解异常,无法形成成熟花粉粒,而在其胚珠发育过程中不育株未能形成成熟胚囊,导致空心胚珠。  相似文献   

6.
一个水稻双子房突变体的表型鉴定和遗传分析   总被引:6,自引:0,他引:6  
在籼稻保持系C2与绵香5B的杂交后代中发现了一个植株显著矮化的双子房突变体。该突变体花器官主要表现为:雄蕊数目减少,雌蕊增加,双子房,多柱头,胚囊畸形,有雄蕊雌蕊化现象。由于其高度不育,突变性状采用杂合体保存,经5代连续自交,均表现稳定遗传特性。同时,杂合株系呈典型的3∶1分离比例,表明该突变性状由单隐性基因控制,并将该突变体暂时命名为TOR。  相似文献   

7.
油菜雄蕊同源异型缺失突变体的发现及形态特征   总被引:1,自引:0,他引:1  
在甘蓝型萝卜质不育系(Ogu CMS)与甘蓝型油菜中双4号和中双9号的杂交后代中,同时发现了花器官同源异型缺失突变体.形态观察表明,该突变体的变异主要发生在花器官第三轮的雄蕊上,其中位于外圈的2枚短雄蕊发育受阻,干瘪皱缩,不能产生花粉;而位于内圈的4枚长雄蕊则全部转化为心皮状结构,紧紧包附在雌蕊的周围.由于这种新型不育材料存在同源异型转换现象(雄蕊转化为心皮),因此推测其产生可能与控制花器官发育的同源异型基因的变异有关.  相似文献   

8.
水稻花粉萌发及花粉管生长动态   总被引:3,自引:0,他引:3  
用显微镜观察水稻花粉粒的萌发、花粉管在雌蕊中的生长以及授粉后不同时间剪除柱头处理对颖花结实率的影响。 水稻花粉粒在授粉2 min后开始萌发;5~10 min后花粉管穿过柱头进入花柱生长;约经30 min花粉管顶端到达子房基部;40 min时有些花粉管顶端可接近胚囊,此时花粉管内胼胝质形成,但数量较少;50 min后花粉管内胼胝质塞大量形成,花粉粒萎缩干瘪。水稻花粉管在柱头、花柱和子房中的生长速率分别为1500、5000、5400 μm/h。水稻授粉后10~15 min剪除柱头的处理只有极少量颖花结实,授粉后20~50 min剪除柱头处理的颖花结实率随处理时间推迟而升高,授粉后50 min剪除柱头处理的结实率达60%以上,接近正常。  相似文献   

9.
王平  吕柳新 《热带作物学报》2009,30(8):1105-1108
将琯溪蜜柚和度尾蜜柚2个品种的雌蕊,分别短截成柱头、花柱和子房3个部位的组织块,移植到培养基上培养,播上本品种或异品种的花粉,通过荧光显微技术,观察雌蕊的不同部位对交配亲和性的影响。结果表明:本品种或异品种的花粉虽然在3个部位组织块上均能正常萌发,但在本品种子房组织块上出现了强烈不亲和反应;琯溪蜜柚在胚囊中观察到因胼胝质积累而出现的强烈荧光。推测子房是2个品种自交不亲和的主要抑制部位,胚囊也是琯溪蜜柚不亲和的关键抑制部位。  相似文献   

10.
以热引1号胡椒为材料,利用形态观察和石蜡切片技术研究了花器官外部形态和内部结构及其发育进程.结果表明:不同发育阶段胡椒花穗长度和质量呈显著正相关,且在20~28 d增长明显变缓.胡椒花为杂性花,兼具雌花、雄花和两性花,但雄花和两性花数量极少.胚珠为直生类型,具短珠柄,着生在中轴胎座上.胚珠和胚囊发育过程长达20d,速度比较缓慢.花穗同一部位雌蕊发育启动比雄蕊稍晚,但柱头在花粉囊破裂之前失活,这种雌雄异熟机制可在一定程度上增加远源杂交比例.  相似文献   

11.
随着早熟晚粳、中熟晚粳广泛种植,水稻轻型省力栽培方式旱直播的推广,病虫也发生了变化,成熟期显著推迟,下茬无法在适宜播期种植,影响粮食丰产稳产。提出筛选早熟当家品种、大力推广机插秧、加大粮食烘干设备的投入、合理施肥、精准植保等对策。  相似文献   

12.
概述了海峡两岸农业交流与合作的现状,提出了应该共同呼吁尽快实现两岸“三通”,开放农业生物技术图书期刊资料交流以及开放生物学科方面网络的思路,以便为农业交流与合作的顺畅开展打好基础,并寄希望能够就糖蔗、果蔗以及甘蔗笋等方面的研究与开发到台湾学习取经,开展学术交流或与台湾同行共同开展研究,为我省甘蔗业的发展作出贡献。  相似文献   

13.
Sorghum and millet phenols and antioxidants   总被引:5,自引:2,他引:5  
Sorghum is a good source of phenolic compounds with a variety of genetically dependent types and levels including phenolic acids, flavonoids, and condensed tannins. Most sorghums do not contain condensed tannins, but all contain phenolic acids. Pigmented sorghums contain unique anthocyanins that could be potential food colorants. Some sorghums have a prominent pigmented testa that contains condensed tannins composed of flavan-3-ols with variable length. Flavan-3-ols of up to 8–10 units have been separated and quantitatively analyzed. These tannin sorghums are excellent antioxidants, which slow hydrolysis in foods, produce naturally dark-colored products and increase the dietary fiber levels of food products. Sorghums have high concentration of 3-deoxyanthocyanins (i.e. luteolinidin and apigenidin) that give stable pigments at high pH. Pigmented and tannin sorghum varieties have high antioxidant levels that are comparable to fruits and vegetables. Finger millet has tannins in some varieties that contain a red testa. There are limited data on the phenolic compounds in millets; only phenolic acids and flavones have been identified.  相似文献   

14.
Sorghum is a good source of phenolic compounds with a variety of genetically dependent types and levels including phenolic acids, flavonoids, and condensed tannins. Most sorghums do not contain condensed tannins, but all contain phenolic acids. Pigmented sorghums contain unique anthocyanins that could be potential food colorants. Some sorghums have a prominent pigmented testa that contains condensed tannins composed of flavan-3-ols with variable length. Flavan-3-ols of up to 8–10 units have been separated and quantitatively analyzed. These tannin sorghums are excellent antioxidants, which slow hydrolysis in foods, produce naturally dark-colored products and increase the dietary fiber levels of food products. Sorghums have high concentration of 3-deoxyanthocyanins (i.e. luteolinidin and apigenidin) that give stable pigments at high pH. Pigmented and tannin sorghum varieties have high antioxidant levels that are comparable to fruits and vegetables. Finger millet has tannins in some varieties that contain a red testa. There are limited data on the phenolic compounds in millets; only phenolic acids and flavones have been identified.  相似文献   

15.
Summary Between 1993 and 1998 205 different potato cultivars and 1220 accessions/genotypes of wild and cultivated potato species from the IPK Genebank Gatersleben were evaluated. Parameters interesting for starch isolation and especially for the use of starch were determined. Altogether, there was a higher variability in wild potato species than in cultivated potatoes for all characteristics investigated: dry matter content, starch content, protein content, amylose content and mean particle diameter of starch granules.  相似文献   

16.
1大豆花叶病毒病 大豆病毒病(Soybean Mosaic Virus,SMV)是世界性病害之一。我国东北地区已鉴定的有5种,即大豆花叶病、顶枯病、蚕豆萎蔫病、南方菜豆花叶病、花生条纹病毒。其中大豆花叶病在全国大豆主要产区都有发生,十分常见。  相似文献   

17.
蔡红 《大豆科技》2001,(3):15-15
近年来,随着大豆播种面积的增长,受病虫危害日趋严重。特别是大豆根潜蝇(又名根明)与根腐病共同发生危害,严重影响大豆的生产。综合防治技术主要手段是三年以上轮作,适时播种及种衣剂拌种等措施。  相似文献   

18.
Yield and quality of winter and spring triticales for forage and grain   总被引:2,自引:0,他引:2  
In field experiments conducted over 2 years in Mediterranean conditions, five winter and five spring triticales were evaluated for forage and grain production in the same cropping season. The experiments had two treatments, namely harvesting for grain only, and dual-purpose forage and grain production. In the latter treatment, forage was cut when the first node was detectable (Zadoks' stage 31), without removing the apical meristems. Grain was harvested when ripe (Zadoks' stage 92) in both cut and uncut plots.
Environmental conditions affected grain production and protein content more than forage yield and quality. Winter triticales yielded about 43% more forage than spring types, but after forage removal the spring types yielded about 36% more grain than winter triticales.
Reductions in grain yield after clipping were more pronounced in winter (32%) than in spring (19%) types. Forage crude protein content was significantly higher in the spring types studied (24.6%) than in the winter types (23.5%), the opposite being true for fibre content (20.7 and 21.6% respectively). Grain crude protein content did not differ between grain and dual-purpose treatments, but was higher in the spring triticales (12.8%) than in the winter types (11.9%). There was more variability for the measured traits within the winter triticales studied than within the spring types.  相似文献   

19.
种子加工、检验理论与技术现状及思考   总被引:3,自引:0,他引:3  
种子加工及检验是种子向市场流通的关键,是商业化育种中赋予种子商品属性不可或缺的环节。种子加工、检验理论与技术的研究是完善种业产业链、实现规模化商业育种、夯实“育繁推一体化”种业科学的重要一环。中国的种业科学技术体系正在形成与完善之中,受制于行业发展水平,种子加工及检验理论与技术相对薄弱。本文回顾了种子加工及检验理论与技术研究发展历程,提出了完善中国种业科学发展的策略与建议。围绕种业发展的需要,在做好品种优质化繁育的基础上,分析种子加工及检验理论与技术的新方向和新需求,加强种业应用性研究,建立先进的种子质量检验体系,研制适合现代种业发展需求的种子加工设备,打造种子加工产业标准化生产体系,完善种业科学技术学科建设,促进种业产业持续健康发展。  相似文献   

20.
Seed processing and testing hold the key to the market circulation of seeds, and are an indispensable link in commercial breeding to endow seeds with commodity attributes. The research of seed processing and testing theory and technology is an important link in improving the seed industry chain, realizing large-scale commercial breeding and consolidating the seed industry science of ‘integration of breeding, propagation and promotion’. The scientific and technological system of seed industry in China is being formed and perfected, which is subject to the development level of the industry. The theory and technology of seed processing and testing are relatively weak. We reviewed the development of seed processing and testing theory and technology, and put forward strategies and suggestions to improve the sound development of China’s seed industry. In order to meet the needs of seed industry development and on the basis of high quality breeding of varieties, the new directions and demands of seed processing and testing theory and technology were analyzed. We will work to strengthen the applied research of seed industry, establish advanced seed quality inspection system, improve seed processing equipment suitable for the development needs of modern seed industry, establish standardized production system of seed processing industry, develop the scientific and technological disciplines of seed industry, and promote the sustainable and healthy development of seed industry.  相似文献   

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