果梅花粉原位萌发及花粉管生长特性的研究

以软条红梅为试材,分别于白花授粉和异花授粉后的1、3、6、12、24、48、72、96、120 h切取花柱,用FAA固定液处理、荧光染色后压片观察,结果表明:异花和自花花粉都能在柱头上萌发,但在授粉后的48 h之内异花花粉的萌发率显著高于自花花粉的萌发率,如在授粉6 h后,异花花粉萌发率高达58％,而自花花粉的萌发率仅为23％。花柱内异花花粉管生长速度明显比自花的快,在授粉后花粉管到达花柱上部、中部及基部的数目均是异花高于白花。如授粉24 h后异花花粉管平均有30余根穿过花柱上部,约有14根到达中部,有2根到达基部;而自花授粉的花粉管分别仅有18、7和0根,且白花授粉时在72 h内均未见有花粉管到达花柱基部,主要在花柱中部前后停止生长。结果表明软条红梅自花授粉的花粉管主要是在花柱中部被抑制而停止生长,从而不能完成受精,表现出典型的配子体型自交不亲和性。     

Gametophytic self-incompatibility causes seedlessness in ‘Kagzi Kalan’ lemon (Citrus limon)

The present study aimed to study the flower and pollen structure, pollen viability, in vitro pollen germination of ‘Kagzi Kalan’ lemon (Citrus limon (L.) Osbeck), and in vivo pollen tube growth in self- and cross pollination to understand the mechanism of seedlessness. The results revealed that Kagzi Kalan had tetra-colporate spherical shaped pollen of uniform size. The results of Acetocarmine and FDA test and in vitro germination indicated normal pollen viability and germinability in Kagzi Kalan. In vivo pollen tube growth showed > 50% pollen germination on stigma in all treatments though a greater number of pollen tubes at the mid style, base of the style, and near the ovule was found in cross pollination. Contrary to this, despite optimum pollen germination (53.51–70.37%) in self-pollination treatments, none of the pollen tubes reached the base of the style due to abnormal growth of pollen tubes, viz. curvatures, inhibition of pollen tube growth, and callose deposition. The inhibition of pollen tubes at the mid style under self-pollination treatments, and production of seeded fruits under cross pollination treatments, indicate the presence of self-incompatibility and the site of inhibition of pollen tubes. Thus, gametophytic self-incompatibility (SI) caused seedlessness in Kagzi Kalan by blocking fertilization in the ovary.     

Effect of temperature on pollen germination and pollen tube growth of four cultivars of mango (Mangifera indica L.)

Summary

The effect of a constant (10, 15, 20 or 25°C) or a diurnal maximum/minimum (15/5, 20/10, 25/15 or 30/20°C) incubation temperature on in vitro pollen germination and pollen tube growth in the pistils of two poly-embryonic (‘Kensington’ and ‘Nam Dok Mai’), and two mono-embryonic (‘Irwin’ and ‘Sensation’) mango cultivars was studied. In in vitro experiments where pollen was incubated in a liquid germination medium for 24 h in darkness, little difference was found between pollen germination of mono- and poly-embryonic cultivars. Averaged over the four cultivars, 53.9% of pollen germinated at 10°C, this increased to 76.2% when the incubation temperature was increased to 15°C, thereafter up to 25°C the percentage germination remained stable but germination decreased slightly to 68.2% at 30°C. Similarly, there was no difference in percent germination between cultivars when pollen was incubated under diurnal temperature regimes. Mean pollen germination of all four cultivars was 52.3% at 15/5°C and pollen germination increased by 10% when the temperature was raised to 30/20°C. When self-pollinated flowers were incubated for 24 h on a semi-solid agar medium at 10°C, pollen tube growth of the four cultivars was retarded and no pollen tubes reached the ovaries. As the temperature was increased from 15 to 25°C, the mean number of pollen tubes in ovaries increased from 0.04 to 0.25. At 30°C, the mean number of pollen tubes that entered ovaries decreased to 0.04. After incubation under diurnal temperature regimes, the mean number of pollen tubes in ovaries of all four cultivars at 15/5°C was 0.23 and increased to 0.42 when the temperature increased to 30/20°C. At each incubation temperature, there were significant differences in pollen tube growth between cultivars, but there were no differences between the temperature response of pollen from mono- and poly-embryonic cultivars.     

Pollen tube growth in macadamia

Pollen tube growth in macadamia was studied by fluorescence microscopy. The cultivars ‘Kakea’, ‘Keauhou’, ‘Hinde’ and ‘Renown’ showed some self-incompatibility, with pollen tube growth arrested in the style. Inhibited tubes had swollen tips and appeared to discharge their contents through a sub-terminal pore. Cross-pollination resulted in a single pollen tube reaching the ovary in from 0 to 48% of the pistils observed. The pollen tube took up to 7 days to reach the ovary. Random samples of open-pollinated flowers were taken from 5 cultivars: ‘Kakea’, ‘Keauhou’, ‘Hinde’, ‘Renown’ and ‘Nutty Glen’. The pistils had fewer ovaries with a pollen tube than those which were hand-pollinated.     

Cross-(in)compatibility in apricot (Prunus armeniaca L.)

Summary

Eight apricot (Prunus armeniaca L.) cultivars and selections were self- and cross-pollinated in order to determine their pollen and stylar compatibility. Overall, 40 pollination combinations were examined. Pollen-tube growth in pistils pollinated in the laboratory was analysed using fluorescence microscopy. Three inter-incompatiblity groups of cultivars were found, of which two had not been described previously, while an existing group was expanded with one additional cultivar. The first group consisted of three Hungarian cultivars (‘Ligeti Orias’, ‘Cegledi Orias’, and ‘Szegedi Mammut’) and a Moldavian cultivar (‘Kostjuzhenskyi’). The second group consisted of two American cultivars (‘Stark Early Orange’ and ‘Nugget’). The third group consisted of two Serbian selections (‘Novi Sad Early’ and ‘Frushka Gora Early’). In the incompatible cultivar combinations, pollen-tube growth stopped in the style with the formation of the characteristic swelling. In the compatible combinations, the pollen tubes reached the ovary in the majority of the pistils examined.     

寒富苹果授粉花柱的荧光显微观察与自交亲和性分析

以寒富苹果为试材,进行自花和异花授粉后花朵和花序坐果率、平均种子数调查试验和荧光显微观察,结果表明,寒富苹果自花授粉的花朵坐果率高达92.8%,花序坐果率为98.3%,平均种子数为7.9粒;略低于异花授粉的96.6%、100%和9.5粒。自花授粉8 h后花粉开始萌发,花粉管能够正常生长,48 h花粉管伸入花柱中部,并在72 h后通过花柱基部,进入子房室。而异花授粉后8 h花粉管开始进入花柱,24 h花粉管伸入花柱中部,48 h花粉管穿过花柱的基部并进入子房室。     

Effect of methanol and gamma irradiation on enzymatic activity of apple pollen

In order to characterize devitalized pollen (which can be used as a “mentor” in mixed pollinations), certain hydrolase activities were spectrophotometrically tested in normal and in methanol or gamma irradiation-treated pollen of Malus domestica Borkh. cultivar ‘Golden Delicious’, and in normal pollen of the cultivar ‘Starkrimson’. Enzymatic activities of methanol-treated pollen were somewhat decreased, except for acid phosphatase which was enhanced over the control. This increase could be due to a higher hydrolysis rate by the alcohol, and/or to enzyme activation after damage of the lytic organelle membranes. Amylase, cellulase, ribonuclease and particularly acid phosphatase activities were stimulated in irradiated pollen. It was hypothesized that there was an enzyme leakage from the lytic compartment following pollen irradiation. On the basis of these data on enzymatic activities, it can be concluded that comparable effects were induced by either methanol or irradiation treatment of apple pollen.     

果梅花不同发育阶段花粉原位萌发及花粉管生长特性

为探明自花、异花花粉在果梅花的不同发育阶段原位萌发及生长的特性,以细叶青果梅为材料,取开花前6、4、2d、开花当天和花后2d的花(花蕾),分别于自花、异花授粉(莺宿)后12、24、48、72、96h切取花柱,用FAA固定液处理,荧光染色后压片观察。结果表明,自花花粉在柱头上的萌发率略低于异花(开花前4d存在显著差异),开花前6、4d极显著低于其他各阶段,花蕾越幼小花粉萌发越差,开花当天花粉萌发率超过80%;开花前4d之前的花柱内异花花粉管数量显著低于开花前2d及之后各期的,果梅开花前4d以前的花发育不充分;开花后2d生长到花柱基部的异花花粉管数量较多,属于有效授粉期。果梅在开花前4d开始具备抑制自花花粉管生长的能力,并且随着花的发育逐渐增强,开花当天最强,开花后开始减弱。果梅自交授粉期以开花前2～3d为宜。     

百合种间杂交受精前障碍的研究

 以‘山丹’ (Lilium pumilum ) 、‘西伯利亚’ ( Siberia) 、‘白狐’ (White Fox) 、‘粉完美’( Pink Perfection) 、铁亚杂种系品种‘达诺’ (Ceb Dazzle) 和‘维多利亚瀑布’ (Victoria Falls) 为试材, 对花粉的活力、萌发力、贮存条件及授粉方式进行了研究, 结果表明适宜的蔗糖浓度有利于百合花粉萌发;花粉贮存适宜温度为5℃; 不同的授粉方式影响花粉的萌发, 授粉48 h后, 花粉管停止生长, 切花柱授粉方式的花粉处于不萌发状态; 试管受精24 h后, 花粉管即可进入胚珠, 45 d果实明显膨大, 经胚培养获得杂交苗。     

Sexual compatibility within and between olive cultivars

Summary

Self- and cross-incompatibility of the olive cultivars Frantoio, Manzanillo, Kalamata, Pendolino, and Picual were investigated using a 5 × 5 diallel matrix. Pistils were collected seven days after controlled pollinations on the day of flower opening, and pollen tubes were detected by fluorescence microscopy. Diallel analysis showed significant specific combining ability, general combining ability and reciprocal effects between cultivars for pollen tube growth in the pistil. ‘Frantoio’ was cross-compatible, as either a male or female parent, with each of the other cultivars, but showed a high degree of self-incompatibility. ‘Manzanillo’, ‘Kalamata’, ‘Pendolino’, and ‘Picual’ were crossincompatible, and all except for ‘Manzanillo’, were self-incompatible. It is concluded that ‘Frantoio’ is a good general polleniser for the other cultivars investigated. Pollen tube growth decreased in discrete steps from stigma to upper style, and from upper style to lower style, with the result that only one, and rarely more, pollen tube penetrated ovules. The sex ratio of flowers, and pollen viability using fluroescein diacetate staining and in vitro germination, were examined. ‘Frantoio’, ‘Manzanillo’ and ‘Pendolino’ had more than 80% perfect flowers, while ‘Kalamata’ and ‘Picual’ had less than 30%. ‘Frantoio’ had the highest pollen viability, ‘Kalamata’ and ‘Picual’ were intermediate, and ‘Manzanillo’ and ‘Pendolino’ the lowest. Pollen staining and both in vitro and in vivo germination provided the same male fertility rankings of cultivars.     

苹果自花授粉的花粉管结构变化及S-RNase定位

 苹果‘红星’品种授粉处理24 h后, 自花授粉比异花授粉的花粉管生长缓慢。授粉处理48 h后, 可观察到自花授粉花柱通道组织的花粉管内有二裂粒子增加、管壁破裂和管内物质溢出、外层管壁增厚等现象。苹果气球状花期未授粉的花柱及自花和异花授粉24 h后且无花粉管存在的花柱切片显示, S-RNase位于花柱通道组织的细胞内。自花和异花授粉48 h后有花粉管通过的花柱切片显示, S-RNase位于花柱通道组织的细胞间隙和花粉管内。     

Effect of low temperatures during flowering on floral cycle and pollen tube growth in nine avocado cultivars

The floral response of the type A avocado cultivars ‘Reed’, ‘Wurtz’, ‘Rincon’ and ‘Jalna’, and the type B cultivars ‘Bacon’, ‘Ryan’, ‘Edranol’, ‘Sharwil’ and ‘Hazzard’ was tested under growth-cabinet conditions of 17° C day, 12° C night, with a 12-h photoperiod and photon flux density of 400 μE m^?2 s^?1 (400–700 nm). Most of the flowers of all type A cultivars and the type B cultivar ‘Bacon’ had both a female and a male stage. None of the flowers of the other type B cultivars had a female stage but opened in the male stage only. Hand pollination resulted in some ovule penetration in the cultivars with female stage flowers. In those with only male-stage flowers, the pollen tubes grew no further than the style. Maintenance of fertility under low-temperature conditions during flowering appeared to be partly, but not entirely, linked to the type A flowering cycle.     

Germination and growth of sponge gourd (Luffa cylindrica) pollen tubes and FTIR analysis of the pollen tube wall

Emergence of multiple pollen tubes from single pollen grains occurred both in vitro and in vivo in sponge gourd (Luffa cylindrica (L.) Roem). The frequency with which pollen grains produced multiple pollen tubes in vivo (7.2%) was lower than that under in vitro conditions (14.9%). In pollen grains germinated in vitro, the total length of the multiple pollen tubes was greater than that of single pollen tubes, but individual tubes among the multiple tubes did not reach the same length as single tubes. Moreover, the growth of the single pollen tubes continued for a longer period in vitro than that of the multiple tubes. Fluorescence microscopy showed that callose was present throughout the pollen tube wall except in the apical part of growing pollen tubes, and nuclei moved into the longest of the multiple tubes. Results of Fourier transform infrared microspectroscopy indicated that abnormal cell wall components (peaks at 800–1000 cm⁻¹) were more frequent in multiple pollen tubes lacking nuclei, and the pectin content (1733 cm⁻¹) in multiple pollen tubes was much lower than that in single pollen tubes. These findings suggested that there were significant differences in pollen tube growth and wall composition between single and multiple pollen tubes, and that multiple pollen tubes had much less opportunity than single pollen tubes to reach the embryo sac and achieve double fertilization.     

Optimal pollination environment of tetraploid ginger (Zingiber officinale Roscoe) evaluated by in vitro pollen germination and pollen tube growth in styles

Pollen germination percentages in vitro of a tetraploid ginger (Zingiber officinale Roscoe), ‘4×Sanshu’, tended to be highest at around 20°C. Pollen tube growth in the styles was greatly enhanced at 17°C, i.e., pollen tubes penetrated into the entire stylar length in 66.7% of the styles used. Pollen stored for at least 3 h under 40–80% relative humidity (RH) almost completely lost its germinability, whereas pollen incubated for up to 3 h under 100% RH retained a relatively higher germinability. Moreover, the pollen germinability that was lowered under 40–80% RH did not recover when the pollen was re-humidified for 2 h under 100% RH before inoculation onto a medium. When stigmas were pollinated with fresh pollen at 17°C under 100% RH, pollen tubes penetrated into the entire stylar length in 26.7% of the styles tested. Under 40–80% RH, however, pollen tubes stopped growing at the middle or the base of styles. From these results, I concluded that the optimal pollination environment of the tetraploid ginger was at 17–20°C under 100% RH.     

杏品种授粉生物学研究

以红丰、新世纪等11个杏品种及特新一号等4个新品系为试材,对自交与杂交亲和性、花粉管形态及花粉、花柱氨基酸组分进行了研究,旨在为杏生产和进一步研究提供科学依据。结果表明:(1)按照白花授粉坐果率≥6％为自交亲和这个标准,红丰、新世纪等10个品种为自交不亲和品种(SI),而特新一号等4个新品系是自交亲和的(SC);(2)选自同一杂交组合不同姊妹系的红丰与新世纪杏品种相互授粉坐果率仅为0~0.73％,属于杂交不亲和;(3)不同品种间相互授粉的坐果率差异很大,据此筛选出特早红、红玉杏及凯特等品种是红丰杏适宜的授粉品种;而新世纪用骆驼黄及金太阳等品种授粉的坐果率最高;(4)自交不亲和组合在授粉后72 h花粉管到达花柱3／4处,末端膨大,停止生长,而自交亲和组合的花粉管可以继续生长,并在授粉后96 h进入子房;(5)自交不亲和品种(系)与自交亲和品种(系)花粉的17种氨基酸含量并无显著差异,而花柱氨基酸的组分与花粉氨基酸组分有所不同,其中自交不亲和品种(系)酪氨酸、苏氨酸、甲硫氨酸和精氨酸含量明显高于自交亲和品种(系),差异显著或极显著。     

Pollen Germination and Pollen-Tube Characteristics in a Range of Apple Cultivars

Pollen-tube growth characteristics are being used increasingly to investigate compatibility relationships in plants. A study was initiated to define more fully the characteristics of compatible and incompatible pollen-tube growth in 40 apple cultivars. Individual reactions varied in detail, but, in general, diploid pollen averaged over 70% germination, triploid pollen less than 10%. Compatible pollen tubes grew rapidly down the style and were characterized by small widely spaced, intermittent callose plugs and the absence of terminal plugs. Incompatible tubes were slower growing, often stopping completely, and had heavy depositions of callose tissue along and at the end of the tube.     

Creating triploid germplasm via induced 2n pollen in Capsicum annuum L.

Summary

2n pollen of diploid chili (Capsicum annuum L. ‘Xianjiao’) was induced by heat shock (35.5?C, 4.h) or low temperature treatment (118C, 48.h). The percentages of 2n pollen were increased to 8.3% and 10.5% respectively. The cytogenetic mechanisms of 2n pollen formation were first division restitution, second division restitution and abnormal cytokinesis. Diploid 2n pollen was less competent than n pollen in fertilization. Only one triploid plant arose from 78 progenies after fertilization by 2n pollen. The four offspring plants of the triploid were diploid. The morphological characters of the triploid and microsporogenesis were also evaluated.     

Comparison of S-RNase,RNase T1, T2, and A effects on growth inhibition and RNA degradation of in vitro-cultured pear pollen

To obtain the basic information on fruit set regulation, effects of several RNases including S-RNase on pollen tube growth and RNA degradation in the tube were studied in the pear. Purified S-RNase from the Japanese pear ‘Kosui’ (S₄S₅) predominantly inhibited the growth of ‘Kosui’ pollen tubes (self) in vitro at 0.28 unit μL⁻¹, but it inhibited ‘Chojuro’ (S₂S₃) pollen (cross) only slightly. The same unit of RNase T₁ (EC 3.1.27.3) clearly inhibited the pollen tube growth, but the action was significantly weaker than that of the S-RNase against the self-pollen. Inhibitory effect of RNase T₂ (EC 3.1.27.1) and RNase A (EC 3.1.27.5) was only slight. The proteins other than the S-RNase extracted from pear style did not have any inhibitory action, though they possessed RNase activity 3.8 times higher than S-RNase. Thus, RNases tested here could not substitute for the S-RNase in specific inhibition against the self-pollen tube growth. Total RNA degradation by each RNase occurred in the pollen tubes as following order; S-RNase (self) ≥T₁ > T₂ ≥ A > S-RNase (cross). Degradation degree of 28S and 18S rRNA was as follows; S-RNase (self) > A > T₁ > T₂ > S-RNase (cross). The degradation of 5.8S and 5S rRNA was; S-RNase (self) > S-RNase (cross) > A > T₂ > T_1. The degree of rRNA degradation was, thus, not always in parallel with the degree of pollen growth inhibition. The S-RNase may degrade not only rRNA but also mRNA essential for pollen tube growth, and may be specifically adapted to inhibit the growth of self-pollen tubes. Therefore, controlling S-RNase amount in the style will produce self-thinning cultivars efficiently, which are unnecessary not only for hand-pollination but fruit-thinning practices in the pear. Practically, cultivar with weak self-incompatibility and small amount of S-RNase, such as ‘Okusankichi’, may be an expecting candidate for breeding self-thinning cultivars.     

Factors affecting the efficacy of agar-based substrates for the study of tomato pollen germination

Summary

The present work examines the effects of substrate additions and incubation conditions on in vitro germination of tomato pollen on semi-solid, agar-based substrates with the ultimate aim of defining a standard semi-solid substrate for tomato pollen germination studies. Partial replacement of sucrose by polyethylene glycol (PEG-6000) for osmotic regulation of the substrate significantly increased pollen germination of both the low temperature-susceptible F₁ cultivar ‘Dombito’, and the more temperature-resistant cv.‘Supermarmande’, to a level that varied according to the season of pollen harvest. In contrast, partial substitution of sucrose by mannitol was inhibitory to an extent that depended on the final concentration of mannitol in the medium. The optimum pH for germination was 6.5 and the optimum incubation temperature was 15°C. Among the vitamins (riboflavin, thiamine, pyridoxine, niacin, pantothenic acid, p-aminobenzoic acid), amino acids (glutamic acid, aspartic acid), casein hydrolysate, plant growth regulators (gibberellic acid, indole-3-acetic acid, indole-3-butyric acid, indole-3-propionic acid, 1-naphthaleneacetic acid, kinetin) and flavonoids (naringin, myricetin, naringenin, quercetin, rutin) tested, a significant increase in pollen germination was induced only by the flavonoids quercetin and myricetin and, to a lesser extent, by indole-3-acetic acid. In contrast, both kinetin and naringenin were inhibitory, as were both amino acids at 100 mg l^–1 and casein hydrolysate (at 1.0 – 10.0 g l^–1). On the basis of the above results, we conclude that, for both tomato cultivars tested, the most suitable semi-solid substrate among those examined was that containing 10% (w/v) sucrose, 15.1% (w/v) PEG-6000 and 1.5% (w/v) agar, with the possible addition of 5 mg l^–1 quercetin, or 5 mg l^–1 myricetin.     

不同发育阶段甜樱桃花授粉后花粉萌发和花粉管生长的差异

选用自交不亲和性程度不同的2个甜樱桃品种莫利和拉宾斯为试材,分别在开花前、开花当天和开花后进行莫利自花、拉宾斯自花和莫利×拉宾斯异花授粉,并于授粉后12、24、48、72、96h切取花柱,用FAA固定,荧光染色后压片观察。结果表明,3个组合的花粉萌发率都以开花当天授粉的最佳,拉宾斯自交和莫利×拉宾斯的花粉管生长状况也以开花当天授粉的最佳,但莫利自交的花粉管生长状况却以花前第4天最佳,花后第4天次之,而当天授粉的最差。因此认为,甜樱桃自交不亲和程度与其雌蕊的发育状态密切相关,蕾期授粉和延迟授粉都能够在一定程度上克服甜樱桃的自交不亲和性,但蕾期授粉的作用更加明显。