‘砀山酥梨’花柱可授性及蜜蜂授粉特性的研究

采用半离体培养法和联苯胺-过氧化氢法研究了‘砀山酥梨’花粉萌发特性和柱头可授性。通过对‘酥梨’的最适授粉时间以及7种授粉处理坐果率的研究,探讨其授粉特性。结果表明：开花后每天酥梨柱头活性最佳的时间是11时至15时,柱头最佳授粉时间为开花后第4~5天;‘酥梨’花粉最适萌发温度为25℃,花粉管生长最有利的温度为22~25℃,在相同温度下,花粉萌发率和花粉管长度随时间增加而增加。7种授粉处理‘酥梨’的花朵坐果率中,没有昆虫授粉的‘酥梨’坐果率为0.48%和0.44%,自然授粉和人工授粉坐果率分别为2.83%和13.05%,‘酥梨’ב雪花梨’组蜜蜂授粉的坐果率为32.95%,新鲜花粉和商品花粉坐果率分别为70.2%和13.05%。由此可见,‘酥梨’是异花虫媒果树,蜜蜂可以在‘酥梨’柱头活性最高时进行授粉,从而提高‘酥梨’的坐果率,同时通过对‘酥梨’花器官生理活性和坐果习性的研究,为‘酥梨’的授粉和生产提供基础资料。     

5个苹果专用授粉品种植物学特征与生物学特性研究

为实现苹果单品种建园,选育适宜专用授粉树,研究了‘道格’、‘绚丽’、‘红丽’、‘满洲里’、‘雪球’5 个观赏海棠品种的植物学、生物学性状、花粉特性及果实品质。结果表明,供试品种盛花期为4 月7—20日,和栽培品种花期相遇,‘道格’和‘满洲里’花期较早,盛花期分别为4月7日、4月9日,‘绚丽’和‘红丽’均为4月12日,‘雪球’为4月20日。供试品种花粉量大,‘道格’、‘满洲里’、‘红丽’、‘雪球’和‘绚丽’分别为13384、13162、7426、6074、6003粒/花药。单果重‘道格’最大(12.98 g),其次是‘雪球’(10.66 g)、‘绚丽’(2.59 g),‘红丽’和‘满洲里’较小（均为2.00 g）。果型指数与单果重趋势基本一致。种子数不尽相同,‘红丽’和‘雪球’为7 颗/果,‘满洲里’6 颗/果,‘道格’和‘绚丽’为4 颗/果。可溶性糖含量以‘道格’最高(18.49%),其次是‘满洲里’(16.33%)、‘雪球’(16.11%)、‘绚丽’(15.98%),‘红丽’较低为14.20%;可滴定酸‘红丽’最高为1.16%,‘绚丽’为0.99%、‘满洲里’为0.90%,‘道格’最低为0.80%。初步认为,供试品种适宜作为国内的苹果专用授粉树。     

Self-pollination vs. cross-pollination in almond: pollen tube growth, fruit set and fruit characteristics

Pollen tubes reaching the ovary, fruit set and the main fruit characteristics of six self‐compatible genotypes (‘Marta’, ‘Antoñeta’, ‘Guara’, ‘Lauranne’, ‘S2332’ and ‘S4017’) of almond were studied after self‐ or cross‐pollination. No significant differences after self‐ or cross‐pollination were found in the number of pollen tubes reaching the ovary, the percentage of ovaries finally penetrated, fruit set and fruit characteristics. The results showed the possibility of obtaining suitable fertilization, yields and quality of fruits by self‐pollination of self‐compatible almond cultivars in a single cultivar orchard.     

桃花粉活性检测和离体萌发特性的研究

果树花粉活力直接影响授粉、受精乃至座果。为了解果树品种的花粉生活力,给引种栽培和杂交育种工作创造有利条件,以桃花粉为试验材料,采用染色方法检测花粉的活性。试验结果表明,含有蓝墨水的花粉培养基,花粉萌发率可以达到64.67%,与对照相比差异不明显,因此该方法比较适合于快速检测花粉活性;固体培养基培养2个品种桃花粉,萌发率比液体培养基培养分别高25%和20%。另外温度、花粉密度、培养基中蔗糖及硼酸浓度都对花粉萌发率和花粉管长度有影响,在温度为24℃、1粒花药/100 μL、10%的蔗糖或100 mg/L的硼酸的条件下,均有利于花粉萌发和花粉管生长。     

Cultivar placement affects pollination efficiency and fruit production in European pear (Pyrus communis) orchards

European pear (Pyrus communis) requires insect pollination among compatible cultivars for fruit production. However, most commercial orchards have a limited number of cultivars arranged in monotypic blocks or rows. This can result in insufficient inter-cultivar pollination. We hypothesise that limitations in pollen transfer among cultivars could be explained by both insect behaviour and orchard design. We compared insect activity and pollination efficiency in two European pear cultivars, in orchards with different designs: (i) cultivars alternated in the same row or (ii) cultivars in separate rows. To assess limitations in pollen transfer, we also compared hand pollination with compatible pollen versus open pollination by insects. Insect visitors mainly foraged on neighbouring trees within a row, with few movements across rows (1%). Honey bees (Apis mellifera) and bumble bees (Bombus terrestris) visited significantly more flowers per tree (8.5 vs. 3) and more trees (2.1 vs. 1.3) than solitary bees (Andrena spp.) and hoverflies. Insect visitors deposited large amounts of pollen (∼500 pollen grains) on flower stigmas regardless of the insect type. Cultivar placement affected inter-cultivar pollination; less incompatibility signs were observed when cultivars alternated in the same row (5%) than when cultivars were in separate rows (38%). We observed limitations in pollen transfer as open pollination resulted in significant reduced fruit set, compared with hand pollination, in ‘Conférence’ (21% vs. 30.7%) and ‘Doyenné du Comice’ (7.2% vs. 16.8%). The foraging behaviour of the insects limited thus inter-cultivar pollen transfer in the orchards with cultivars in separate rows. Cultivars used for pollination (pollinizers) should be planted in the same rows as the main cultivar to increase inter-cultivar pollination.     

红丁香的花部特征与繁育系统

通过对红丁香的花部特征观测、花粉形态扫描、花粉-胚珠比测定、柱头可授性测定、杂交指数判定及人工授粉实验,研究了红丁香的花部综合特征与繁育系统类型。结果表明:红丁香花期为5月底至6月初,单花花期5～6d;单花干柱头缩入式雌雄异位,长椭圆形、网脊光滑。雄蕊2～3枚,贴壁生长,花粉三孔沟;红丁香的花粉活力在开花第1天最高,之后逐渐降低,第5天活力丧失;柱头可授性先上升后下降,第4天达到顶峰;杂交指数(OCI)为4,P/O值为9 500,结合人工授粉实验认为,红丁香自交授粉部分亲和,异株授粉座果率高,其繁育系统属兼性自交,以异交为主,需要以昆虫作为传粉媒介。估算发现,红丁香单花序潜在的种子产量为8.6g,而实际花序的种子产量为2.3g左右,只占潜在种子产量的26.3%,具有巨大的提高产量空间。     

不同蜂种授粉对‘金茶1号’茶叶籽传粉效率与果实品质的影响

蜜蜂授粉对农业生产具有非常重要的价值,为了研究不同蜂种授粉对茶叶品质的影响,本研究以茶树‘金茶1号’为研究对象,分别使用意大利蜜蜂(Apis mellifera Ligustica)、中华蜜蜂(Apis cerana cerana)与地熊蜂(Bombus terrestris)开展蜂媒授粉技术及增产提质影响研究。结果表明中蜂授粉组访花频率最高,意蜂授粉组柱头花粉数最高,地熊蜂授粉组单花访问时间最长。中蜂授粉能显著提升茶树的茶叶籽座果率与茶叶籽油茶多酚含量,但对茶叶籽的含油量影响不显著。意蜂授粉与地熊蜂授粉对座果率影响不显,但能显著提升茶叶籽的茶多酚含量与含油量,3个授粉组对茶叶籽油的主要成分并无显著影响。在实际中可以根据生产需要选择对应的蜂种进行授粉。     

Compatibility and incompatibility in witloof chicory (Cichorium intybus L.). 4. Formation of self-seeds on a self-incompatible and a moderately self-compatible genotype after double and triple pollinations

Summary After double or triple pollinations including selfing and the use of one-day-old compatible foreign pollen a severely self-incompatible clone could be forced to develop a reasonable amount of self-seeds per flower head. This number of self-seeds increased when the foreign pollination was delayed for e.g. 240 minutes in the double pollination experiment. Even more self seeds were obtained in the triple pollination experiment with a delayed second selfing.The influence of the old foreign pollen may be caused by a mentor pollen or a pioneer pollen effect.     

Bud pollination and hybrid seed production in detergent-induced male sterile plants of Brassica juncea

The efficacy of a synthetic detergent (Surf Excel) as a potential chemical hybridizing agent in Brassica juncea was studied. Foliar sprays with various concentrations of the detergent caused reductions in plant height, number of branches and leaves per plant, size of leaves, anther size, pollen per flower, ovules per flower, pollen fertility, fruits per plant, fruit size, seeds per fruit, total yield per plant and 100 seed weight as compared with those of untreated plants. The style in the floral buds of plants sprayed with different concentrations of Surf Excel elongated and so the receptive stigma protruded from the buds which facilitated cross‐pollination by honey bees. The plants sprayed once with 2% Surf Excel exhibited an elongated style with a raised receptive stigma and 100% pollen sterility without causing a significant reduction in total yield.     

Induced mutants of Cox's Orange Pippin apple with apparent increased self-compatibility. 2. Laboratory and orchard assessment and testing

Summary Fruit set on clones of Cox's Orange Pippin apple which had been produced by gamma-irradiation, and found in a previous trial to crop when isolated from the pollen of other cultivars, was compared after open or hand-pollination. Some clones set more fruit than the unirradiated control trees when open pollinated or when hand-pollinated with pollen from the same tree or control Cox trees. Pollen from some mutant clones also improved set on standard Cox (EMLA). Estimates of the numbers of pollen tubes reaching the base of the style indicated that the increased set was due to enhanced tube growth.     

Association between sporophytic reaction to Alternaria helianthi and gametophytic tolerance to pathogen culture filtrate in sunflower (Helianthus annuus L.)

Seven sunflower genotypes comprising of populations and hybrids showing differential sporophytic reaction to Alternaria leaf and stem blight were studied for their gametophytic reaction to pathogen culture filtrate. The sunflower pollen grains germinate well in the liquid medium and give good pollen tube growth in the absence of the culture filtrate. The addition of increasing concentrations of culture filtrate to medium significantly reduced the pollen germination and tube growth in all the genotypes. The reduction in pollen germination and tube growth in vitro due to culture filtrate was more in highly susceptible genotypes L-101 and Morden than the moderately resistant genotypes Acc. nos. 1229, 180 and ISFH-306. Pretreating the stigma and style with the culture filtrate before pollination reduced the number of pollen grains germinating compared to untreated control suggesting toxin stress can be created on the stigmatic surface before pollination. There was correspondence between pollen germination on stressed stigma (in vitro) and sporophytic reaction of the genotype suggesting pollen grain having resistance would germinate on the stressed stigma and fertilise the ovule achieving selective fertilisation. The correlation analysis indicated that there is a negative relation between sporophytic per cent disease index value and gametophytic parameters such as in vitro and in vivo pollen germination, culture filtrate required to inhibit 50% pollen germination and pollen tube growth. The association between pollen and the sporophytic reaction to the disease indicate the possibility of rapid screening of a large number of genotypes by means of pollen assay as an alternate technique with regard to sporophytic disease index in sunflower. The study also indicate the possibility of pollen selection before fertilisation to achieve rapid improvement in disease resistance. This revised version was published online in August 2006 with corrections to the Cover Date.     

梨不同树形的结构特征、产量分布及果实品质差异

摘要：研究了湖北省梨产区3种主要树形的个体结构、群体特征、产量分布及果实品质差异。结果表明：单层开心形、双层开心形、小冠疏层形的叶面积指数、树冠覆盖率、叶果比、田间产量均不相同;田间产量主要分布在1.0～2.0m冠层内;同一树形树冠内果实单果质量、可溶性固形物含量、果实硬度等指标从树冠下部到上部逐渐增大,可滴定酸含量则逐渐减少;单层开心形的果品质量优于其他2种树形。     

Gamma-irradiation of cacao (Theobroma cacao L.) pollen: Effect on pollen grain viability,germination and mitosis and on fruit set

Summary Theobroma cacao pollen fertilization capability was studied after 0, 50, 100, 200, 500 and 1000 Gy gamma-irradiation. For all irradiation doses, no alteration of pollen grain viability and in vitro germination was observed. In situ, for all doses, pollen tubes penetrated into the styles and reached the ovules 20 hours after pollination. In vitro observations of the pollen grain nuclei after 20 hours incubation showed that pollen irradiation causes inhibition of the division of the generative nucleus. Fruit survival rate 30 days after pollination decreased as irradiation doses increased from 0 to 100 Gy, and over 100 Gy no fruit set was obtained. The possibility of using irradiated pollen as a method for obtaining haploid cacao plantlets is discussed.     

Drought tolerance in sorghum by pollen selection using osmotic stress

A pollen selection study for drought tolerance using Poly Ethylene Glycol (PEG) as a selective agent was conducted in sorghum. Ten genotypes of sorghum suitable for post rainy season were crossed to cytoplasmic male sterile line 104A and three genotypes to 116A producing 13 hybrids. Two sets of 13 hybrids with and without pollen selection were produced. PEG at 36 per cent was applied to stigma and stylar tissue one hour before pollination for pollen selection (selective fertilization) and no treatment for control (nonselective fertilization). Hybrids thus produced through selective and non-selective fertilization were tested in moisture stress environment during post rainy season. The hybrids obtained through selective fertilization produced significantly higher mean grain yield compared to hybrids obtained through non-selective fertilization. The results indicate that selective fertilization through in vivo pollen selection using PEG as selective agent was effective in improving moisture stress tolerance of the progeny in sorghum genotypes studied. Further, the pollen selection also had influence on plant height, panicle length, panicle width, panicle weight and grain mass. Thus,the pollen selection had a significant effect on grain yield through its components and developmentally related traits. Pollen selection for osmoticstress tolerance in sorghum influences the growth and vigour of the plants resulting in superior progeny in moisture stress environment. The analysis of individual crosses indicated that pollen genotype selection was able to favour performance of the progeny. However, the pollen selection had positive effect in majority of the hybrids and the study demonstrates the transmission of the selected trait from pollen generation to progeny. This revised version was published online in July 2006 with corrections to the Cover Date.     

Yield Components of Apical and Subapical Ear Contributing to the Grain Yield Responses of Prolific Maize at High and Low Plant Populations

Subapical ears are largely responsible for grain yield variations in prolific maize (Zea mays L.) grown under conditions favourable for the expression of prolificacy trait, but limited information exists on yield components contributing to yield responses. A field experiment was conducted to determine the yield components of apical and subapical ear in prolific maize after various pollination treatments at two plant populations. Hybrid Pioneer 3733 was grown in the perfect stands of 71 428 and 35 714 plants ha^?1. Three pollination treatments were carried out: (i) free pollination; (ii) subapical earshoots were covered to prevent pollination; and (iii) apical earshoots were covered to prevent pollination. Grain yields of free pollinated plants were by 50.1 % larger at low plant population (265 g per plant) than at high plant population (177 g per plant) due to a 45.3 % increase in kernels per plant, whereas 1000‐kernel weight slightly increased by 3.3 %. These increased kernels per plant at low plant population were, in part, the result of kernel increments on apical ear (10.1 %), and mainly associated with kernels from subapical ears that did not occur at high plant population. At low plant population, the total grain yield per plant was reduced by 94 g (35.5 %) after the apical ear was bagged to prevent pollination, but only 52 g (19.6 %) when the subapical ear was bagged. When subapical ear development was stopped at low plant population, grain yield on apical ears increased by only 3.9 % as a result of heavier 1000‐kernel weights, clearly demonstrating limitations in kernel set and size. After grain development on apical ear was prevented, subapical ear enlarged to 80.3 % of maximum apical ear yield because the former had, on average, 2.5 % lighter 1000‐kernel weight and 17.5 % fewer kernels than the latter. Ears did not differ in row number when only apical or subapical ear was developed on plant, whereas subapical ears tended to have fewer rows than apical ears when both were present on the same plant. Our results showed that: (i) plant population affected all yield components on both apical and subapical ear except row number; (ii) the occurrence of subapical ear is triggered by achieving maximum potential kernel set on apical ear; and (iii) subapical ear is inferior in potential grain yield to apical one even when the latter was prevented from pollination.     

Production of Homomatromorphs through Pollen Treatment in Pisum sativum L.

The occurrence of homozygous matromorphic progenis in Pisum sativum L. has, been assessed by using heterozygous female parents in intervarietal and intergeneric crosses. The pollen was subjected to three treatments, i.e. prickle pollination (delayed), gamma irradiation and giibberellic acid (GA₃) application, The genetic status of the induced matromorphic progeny was determined by using, multiple gene markers. The frequency or occurrence of homomatromorphs was 3 to 7 per cent, which needs to be increased by pod, ovule or embryo culture, respectively.     

水肥调控对宁夏旱砂地枣树生长发育的影响

以种植在宁夏中卫市香山干旱山区压砂地的3年生‘同心圆枣’树（行间套种西瓜,每公顷产量12000 kg~13500 kg）为试材,研究了保水剂+补水补肥对土壤含水量、坐果率、产量、品质、水分利用率和树体营养生长的影响,试验结果表明：每株施30 g~60 g保水剂,并在枣树生长期补水补肥2次,使整个生育期40 cm处土壤含水量绝对值提高了2.14%,单叶面积增加了4.1%~50.5%,叶绿素含量增加了44.9%（与放任生长的树相比）,坐果率提高了9.5%~27.8%,单株坐果量提高了29.5%~33.2%,单株产量提高了37.9%~51.1%,平均单果重增加了0.5 g~2.1 g,水分利用率提高了33.3%~46.7%,果实固酸比增加了23.0%~41.8%、维生素C含量略有增加,新枣头粗度和主干增粗率也略有增加。     

Soil Properties, Micrometeorological Parameters, Forage Yield and Phosphorus-Uptake of Berseem as Influenced by Phosphate Application under Agroforestry System of Production

The field study of berseem ( Trifolium alexandrinum L.) in association with trees indicated that forage production was highest under Hardwickia binata allowing 80 per cent PAR of open as compared to Acacia tortilis and Leucaena leucocephala with 65 and 48 per cent PAR respectively. The forage yields of berseem were 78, 57 and 36 per cent under Hardwicka, Acacia and Leucaena respectively to that under non-tree association (open canopy). The tree associations helped in improving soil productivity. Organic carbon, available nitrogen and phosphorus, field capacity and soil porosity increased, whereas EC and bulk density decreased under plots with tree associations in the order of Leucaena followed by Acacia and Hardwickia. The phosphate application improved the forage yield and P uptake and utilization. It has also helped in higher organic carbon and available N and P content of soil and also improved the water retention properties of soil by increasing field capacity and pore space and lowering the bulk density, P application to crops at increased rates also reduced the ill effects of radiation curtailment under tree canopy to some degree. The forage yields of berseem were greatly influenced by P application under both the canopy systems (tree and non-tree).     

Variability and early selection on the seedling stage for agronomic traits in progenies from olive crosses

Yield per tree, ripening date and oil content components (fruit fresh weight, flesh moisture, flesh/stone ratio both on fresh and dry weight basis, flesh and fruit oil content on dry weight basis) have been studied during 3 years in seedlings from crosses among the olive cultivars ‘Arbequina’, ‘Frantoio’ and ‘Picual’. Genetic and environmental variances and year‐to‐year consistency of data were estimated. Most of the traits evaluated showed a range of variability as large or even larger than either the range observed in a random sample of cultivars from the World Olive Germplasm Bank of Cordoba or the range reported in the evaluation of olive cultivars collections. Between‐years correlation coefficients showed that for a character such as oil content the values obtained in the first year could be reliable indicators of the values obtained in following years. Observations over 2 years may be required for characters such as fruit weight or flesh/stone ratio on a fresh weight basis and even more than 2 years may be required to estimate yield per tree.     

不同树龄2种树形库尔勒香梨树的冠层花果分布特性

为了明确不同树龄和不同树形库尔勒香梨树的花果在树冠中的分布特征,为库尔勒香梨树的科学整形修剪提供理论依据,以12、23、47年生的2种树形（开心形和疏散分层形）库尔勒香梨树作为研究对象,统计并比较了其单花序花数量、单株总花朵和果实的数量及其分布特性的差异性。结果表明,树形对库尔勒香梨花序花量的影响不太明显,而不同树龄库尔勒香梨树的花序花量有明显差异,12、23、47年生库尔勒香梨树的花序花量分别以4朵、7朵、6朵为主。不同树龄疏散分层形树的花数量和花量分布密度均高于开心形树,其中23年生树的差异最大,47年生树的差异不大。不同树龄疏散分层形树的坐果率和果实分布密度也均明显高于开心形,尤其是12、23年生疏散分层形树的果实分布密度比开心形树高几倍到几十倍,而47年生树的差异不太明显。在初果期和盛果期疏散分层形是库尔勒香梨树高产稳产的理想树形,而在老龄期推荐改成开心形。