甜菜单胚雄性不育系及保持系雌蕊形态学及细胞学研究

以甜菜单胚雄不育系和保持系为材料，用光学显微镜对其雌性器官各部发育进行了比较解剖学观察．结果如下：甜菜雌蕊由3—5枚心皮合生而成，外形可分为柱头、花柱和子房三部分。各部解剖学特征：（1）柱头3—5枚离生稍向外生长，柱头正面由大量乳突细胞组成；（2）花柱短小，半开放形，开口较小，其内充满腺毛状结构；（3）半下住子房，心皮合生一室，在外侧愈合交界处，有发达的盘状蜜腺；胚珠1枚基底胎座，曲生形胚珠，双珠被厚珠心．蓼形胚囊，并有盲囊结构产生。研究表明，甜菜雄不育和可育的雌蕊、胚珠、胚囊形态结构相似，均可正常发育，两者均具有受精与结实能力．     

甜樱桃胚珠、花粉发育与温度变化的关系

为探明甜樱桃性细胞发育规律及其所需的温度条件,利用石腊切片方法观察了露地栽培条件下,甜樱桃胚珠、胚囊和花粉发生发育过程的形态变化特征及其所需最低和最高温度。结果表明,甜樱桃的胚珠、胚囊和花粉发育,是在春季伴随着温度逐渐升高完成的;花前21￣35d,随着气温的升高,小孢子母细胞由相互连接在一起逐渐分离呈游离状态,在开花前21d的萌芽期前后完成2次分裂,由一个细胞分裂成四个细胞(四分体)形成花粉粒,此过程是在较低的温度(-0.1￣12.8℃)条件下完成;萌芽以后,胚珠的发育速度加快,开花前14d左右完成胚珠发育过程,胚囊的形成是在开花前7d内完成;甜樱桃的胚珠由单层珠被、珠心及胚囊构成。试验结果可为甜樱桃设施栽培的温度管理提供参考。     

露地和日光温室甜樱桃花芽发育特征及胚珠多糖定位观察

通过观察‘早红宝石’从萌动期至谢花期的花芽发育特征及胚珠多糖定位,进一步探讨高温造成甜樱桃胚囊败育原因。结果表明,在同一物候期,露地、温室、破眠剂处理的花芽发育特征及胚珠淀粉粒定位一致;在同一物候期,温室‘早红宝石’胚珠淀粉粒数量多于露地和破眠剂处理的,分布区域也大于后两者;破眠剂处理的花后2 d胚珠淀粉粒数量多于对照,分布区域也增加。分析认为,温度是决定甜樱桃花芽发育进程、胚珠多糖数量及分布的重要因素。高温加速花芽发育,却抑制胚珠多糖水解,难以满足胚珠、胚囊快速发育对碳水化合物的需求,最终胚囊败育。破眠剂可提早花芽发育进程,有效提高胚囊发育质量,其生物学效应类似于某种高温逆境逃避机制。     

甜樱桃花芽分化后期特征观察

通过品种比较、地区比较和人工环境模拟3个关联的试验设计,观察甜樱桃从落叶后至谢花后的花芽分化发育的特征,探求其南引试栽、结实困难的原因。结果表明,郑州的早红宝石、红灯和拉宾斯,烟台、郑州和金华的红灯,以及花芽分化期置于露地和日光温室中的早红宝石在多个物候期阶段的最终分化发育的基本特征一致。因此,造成甜樱桃南引试栽、结实困难的主要原因可能与生长季的花芽分化无关,不能仅限于与花前高温引发的胚珠、胚囊发育不良有关,低温累积量不足也是不可被忽视的因素。     

矮生菜豆的种子败育和果荚脱落

通过对开花前后大量子房的切片观察发现，造成果荚脱落的原因是子房未受粉和正常受粉子房中多数种子的发育。其中造成种子败育的原因是：1.胚囊发育不正常；2.正常胚囊未受精；3.单受精；4.胚和胚乳的败育。     

槜李雌蕊形态及早期胚胎发育研究

采用常规石蜡切片法对槜李雌蕊形态和早期胚胎发生发育进行了研究,以期从生殖生物学角度探讨影响槜李低产的原因。结果表明,槜李花柱实心,子房1室,横生胚珠,双珠被,厚珠心。雌蕊胚囊在盛花时仍处在2～4核期。观察的材料中,绝大部分胚囊在盛花后3d发育为成熟胚囊,胚囊蓼型。合子约休眠2～3d后开始分裂。胚乳在盛花7d后出现,八分体原胚出现在第12天。胚胎发生发育过程中有珠心珠被退化、成熟胚囊结构异常等现象。     

黄金梨胚珠、花粉发育及花粉败育过程的显微观察

观察了黄金梨的胚珠、胚囊、花粉发生发育过程中细胞形态变化特征。结果表明:黄金梨的胚珠、胚囊、花粉发育是在春季萌芽到开花过程中完成的。在开花前28d花芽萌动初期,胚珠原基出现,花药囊内为小孢子母细胞;花前21d胚珠原基分化出内外珠被,四分体开始出现;花前14d四分体出现率最高;开花时胚囊形成,花粉败育并形成空花药囊。造成黄金梨花粉败育的原因是小孢子母细胞减数分裂后形成的四分体及四分体分离后形成的早期花粉细胞无细胞核,早期花粉细胞液化不能形成较厚硬的外壁而解体。     

粉绿铁线莲花芽分化研究

利用石蜡切片法对粉绿铁线莲(Clematis glauca)的花芽分化过程进行了观察。结果表明,其形态分化阶段可分为未分化期、分化初期、花被片分化期、雄蕊分化期和雌蕊分化期。各轮花器官为向心式发生,向心式发育。在性细胞分化成熟阶段,雄配子体先于雌配子体发育完全。花药4室,花药壁发育类型为双子叶型,具腺质绒毡层。胞质分裂为同时型,以四面体型四分体为主,花粉粒为2–细胞型。成熟花药中表皮细胞退化或仅余残迹,花药壁仅由纤维状加厚的内皮层构成。子房1室,内含少量退化胚珠及一发育正常的胚珠,倒生,单珠被,薄珠心,蓼形胚囊,具线形四分体及双核反足细胞。在铁线莲属植物中,粉绿铁线莲可能处于相对进化的过渡地位。     

应用胚珠切割及子房透明技术观察无融合生殖甜菜M14胚囊发育

介绍了一种快速简便观察分析无融合生殖甜菜胚囊发育过程的制片法。通过剥离胚珠,并对胚珠珠孔端进行再次切割和分离,经过固定和脱水,用冬青油整体透明及丁香油封片,在OLYMPUS—BX51型荧光显微镜下通过荧光技术观察发育中的胚囊产生自发荧光,可分辨出胚囊的内部结构。用FPA和4％戊二醛两种固定液效果不同．后者效果更佳。     

氨基乙氧基乙烯甘氨酸( AVG) 处理对‘巨峰’葡萄胚珠和种子发育的影响

 ‘巨峰’葡萄开花前2 周用氨基乙氧基乙烯甘氨酸( 2-aminoethxyvinlglycine, AVG)100 mg!L^-1处理可以明显增加有核果粒率和种子数。人工授粉24 h 后, 子房中的花粉管伸长快于对照, 花粉管生长状况也优于对照。这是由于AVG 处理降低了雌蕊中阻碍花粉管伸长物质的活性, 同时可以改善胚囊发育, 提高正常胚囊率和增加子房中的胚珠数和心皮数, 这可能为促进受精和增加受精机会创造了条件。     

影响南京甜樱桃坐果的关键时期

研究不同生育期的生态条件对甜樱桃花芽分化和坐果的影响,确定导致南京地区（年均温 > 15 ℃）甜樱桃坐果率低的关键时期,将郑州的一部分4年生盆栽结果甜樱桃运至南京生长1年后,然后将郑州和南京两地的盆栽苗分别在落叶期、休眠结束后进行双向位置交换,采用石蜡切片法观察花芽和胚囊形态发育,并在果实着色期观察坐果率。结果显示：全生育期在郑州、落叶期由郑州运至南京、休眠结束后由郑州运至南京、全生育期在南京、落叶后由南京运至郑州的‘早红宝石’甜樱桃坐果率分别为38.2%、14.7%、12.9%、8.9%和31.7%;无胚囊的比例分别为41.5%、55.6%、57.7%、74.5%和50.0%;全生育期在郑州和落叶后由郑州运至南京休眠结束后再运回郑州的甜樱桃‘萨米脱’的坐果率分别为13.9%和18.8%。结果表明：影响南京地区甜樱桃坐果的关键时期应是春季开花坐果期;而对于一些能满足需冷量的品种,休眠期对坐果率的影响不大;夏季花芽分化期的高温影响花芽分化进程及分化质量。     

Flower emasculation accelerates ovule degeneration and reduces fruit set in sweet cherry

Flower emasculation is commonly used to make flowers unattractive to pollinating insects and to carry out controlled pollinations. In sweet cherry, we have observed recurrent low fruit set after flower emasculation and compatible pollination without apparent causes. This led us to evaluate its effect on the progress of the reproductive phase and on fruit set in this species. Flower emasculation reduced by more than a half the fruit set obtained in crosses made during two consecutive years. This effect could be traced back to the first week after anthesis where weight increase of pistils from emasculated flowers was smaller and ovule degeneration was accelerated compared to pistils from non-emasculated flowers. Pollen tubes, which behaved similarly at the stigma-style level in emasculated and non-emasculated flowers, lost their directionality in the area close to the degenerated ovule in the ovary. While flower emasculation is valid to evaluate pollen tube performance in the style and to determine incompatibility relationships, the lower fruit set registered after emasculation alerts on its use in fruit set experiments and breeding programs.     

Mechanism of seedlessness in Iranian seedless barberry (Berberis vulgaris L. var. asperma)

Species of barberry (Berberis vulgaris L. var. asperma) is cultivated in arid and semi arid areas of Iran (South Khorasan province). It is widely used as a food additive. Fruits of this species are seedless, while wild type barberries produce seeds in the same area. In this study, we investigated the mechanism of seedlessness in seedless barberry by pollen viability test, field pollination experiments and microscopic observation of pollen tube growth in pistil and ovule development. For comparison, we also examined ovule development in wild type barberry (B. crataegina DC). In seedless barberry pollen germination was about 54%. Seedless barberry produced 20% seeded fruits when pollinated with pollen of wild type barberry. There was a sharp decrease in fruit set in emasculated unpollinated flowers of seedless barberry. In seedless barberry, a large number of pollen grains (about 370) were observed on stigma of each flower at 12 h after balloon stage (ABS). Most of them germinated and penetrated intracellular area of stigma surface, but no pollen tube reached ovary. In seedless barberry, many ovules did not have any embryo sac or had a very small incomplete embryo sac. In addition, unfused polar nuclei were clearly recognized in some cases at 14 days after full bloom (AFB). However, in wild type, double fertilization was accompanied by disappearance of polar nuclei. In seeded barberry, the cellularized endosperm became apparent at seven days AFB. At 21 days AFB, all ovules of seedless barberry were degenerated, while at the same time in wild type, one or two ovules of each flower were normal and were developing into complete seeds. Results showed that self-incompatibility has a main role in seedlessness of seedless barberry. However, the high frequency of abnormal ovules and single fertilization can be considered as two other reasons of seedlessness. Due to our results, fruits of seedless barberry were set by stimulative parthenocarpy.     

亲本品种对樱桃远缘杂交亲和性及胚抢救的影响

以3个甜樱桃品种为母本,3个中国樱桃品种为父本进行了种间远缘杂交,并对所得到的杂种成功地进行了胚抢救,探讨了不同亲本品种对大樱桃远缘杂交亲和性及其胚抢救的影响。结果表明,(1)不同杂交组合的坐果率差异显著,在同一母本的杂交组合中,均以五莲红樱桃作父本的杂交组合坐果率最高(≥4.14%);而以红灯为母本与3个父本品种杂交的平均坐果率高于那翁和先锋为母本的相同杂交组合的平均坐果率;(2)不同亲本品种的杂种胚萌发生长率与多丛芽增殖系数存在显著差异,其中在参试的3个父本品种中,以五莲红樱桃表现最好;(3)经过生根培养,已经成功地将一批杂种胚培苗移栽到大田。     

Contributing to the knowledge of the fertilisation process in four apricot cultivars

Causes of poor crops in apricot were investigated by studying the reproductive process after pollination. The evolution of the ovules and the growth of the pollen tubes were determined. Also the fertilisation of the ovules and the fruit set obtained, when pollination was delayed, were examined in two groups of cultivars with different fruiting behaviour. ‘Beliana’ and ‘Palstein’, two cultivars that consistently set good yields, presented ovules that mature earlier and in larger number than those of ‘Guillermo’ and ‘Bergeron’, characterised for year-to-year low fruit production. Pollen tubes also grew faster in the first group of cultivars. Differences found between both groups of cultivars, seem to be related to the ability of the ovules to develop and mature after anthesis, and around 50% of them only had a mother cell without an embryo sac, suggesting that development of those ovules was stopped at an early stage. This fact critically influenced fertilisation and, therefore, fruit set. There seem to be a good correlation between percentages of mature ovules a few days after anthesis, the percentages of fertilised ovules and final percentages of fruit set.     

Effect of high temperatures in the pre-blooming and blooming periods on ovule formation,pollen grains and yield of ‘Granada’ peach

The aim of this work was to evaluate the effects of high temperatures in the pre-blooming and blooming periods on the growth of sexual gametes and yield of ‘Granada’ peach. The experiment was carried out in the commercial orchard of Charqueadas, under the subtropical conditions of the Central Depression at Rio Grande do Sul State, Brazil (28°57′S; 51°37′W; 30 m alt.). Two treatments were tested: (1) trees in the greenhouse with partial ventilation and (2) trees in the orchard. The phenology, morphologic constitutions of the pollen grains, ovule growth, yield and germination (%) of pollen grains and fruit set were evaluated. High temperatures in the pre-blooming and blooming periods anticipated the break of dormancy and blooming. These conditions also delayed the female gametophytes (embryo sac) and promoted anomalies in the formation of male gametophytes. Those factors promoted low pollen viability and a lack of synchrony in fertilization, thereby generating low fruit set percentages and yield.