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.     

Regulation of some biochemical attributes in drought-stressed cauliflower (Brassica oleracea L.) by seed pre-treatment with ascorbic acid

Cauliflower (Brassica oleracea L. var. botrytis) is widely used as a vegetable in many countries; however, productivity is adversely affected in areas affected by drought. To investigate the role of exogenously applied ascorbic acid (AsA) in mitigating the negative effects of drought on cauliflower, a pot experiment was performed using two cultivars of cauliflower ‘Local’ and ‘S-78’. Seeds of both cultivars were soaked in 75 mg l^–1, or in 150 mg l^–1 AsA, or in water (control) for 16 h. Water-deficit stress suppressed plant growth, reduced leaf chlorophyll concentrations, relative water contents (RWC), shoot and root P and K⁺ ion concentrations, and total soluble protein concentrations, significantly. However, significant drought-induced increases were observed in relative membrane permeability (RMP), the accumulation of total phenolic compounds, leaf free proline, glycinebetaine (GB), endogenous AsA, and hydrogen peroxide concentrations, and in the activity of superoxide dismutase (SOD). Seed treatment with 75 or 150 mg l^–1 AsA resulted in lower accumulations of H₂O₂, while increasing shoot and root fresh weights and dry weights, RWC, total phenolic compound, free proline, GB, and endogenous AsA concentrations, and the activities of SOD and catalase (CAT). No changes were observed in leaf chlorophyll concentrations or in peroxidase (POD) activities, RMP, shoot and root P and K⁺ ion accumulation, or in total soluble protein concentrations under water stress or non-stress conditions following seed treatment with AsA. ‘Local’ had higher proline concentrations and SOD activities; however, ‘S-78’ had higher RWC values, GB, and AsA concentrations. Overall, a pre-sowing treatment of cauliflower seed with 75 or 150 mg l^–1 AsA improved seedling tolerance to drought stress in both cultivars, which could be attributed to AsA-induced decreases in RMP and H₂O₂ concentrations, increases in the activities of CAT and SOD, increased RWC, and higher total phenolic compound, proline, GB, and AsA concentrations. The exogenous application of AsA therefore offers an effective strategy to minimise the adverse effects of drought stress on vegetable crops, including cauliflower.     

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.     

Effects of putrescine application on fruit set in ‘Housui’ Japanese pear (Pyrus pyrifolia Nakai)

In Japan, artificial pollination is practiced to improve fruit set as well as fruit size and to obtain perfect round shapes in ‘Housui’ (S₃S₅) Japanese pear and most commercial cultivars that present gametophytic self-incompatibility. The period of artificial pollination application is limited by environmental conditions and the availability of a labor force. The present study aimed to determine if pre-pollination applications of putrescine (1.0 and 0.01 mM) positively affect fruit set in ‘Housui’ after hand-pollination. During 2002 and 2003, fruit set in late pollinated flowers increased with pre-pollination putrescine applications and concentrations of 1.0 mM had a better effect than 0.01 mM. In vitro pollination tests revealed that higher pollen germination was present in the stigmas of flowers sprayed with 1.0 mM of putrescine compared to the controls. Putrescine application did not affect post-pollination ethylene production in the styles. Moreover, in the styles of non-treated flowers, an increment of putrescine content and ethylene production after pollination was found, suggesting post-pollination responses and confirming the lack of antagonism between polyamines and ethylene at least during this process.     

Influence of pistil extract and temperature on in vitro pollen germination and pollen tube growth of olive cultivars

In vitro tests for pollen germination and pollen tube growth of olive cultivars were carried out with the addition of pistil extracts. Low pistil extract concentrations (.0.3–0.6 mg ml^-1 f.w.) enhanced pollen germination and pollen tube growth for the same or different cultivars. Different responses to temperature were observed when pollen and pistil extract belonged to the same or to different cultivars. The results suggest that this in vitro test could be used to assess compatibility groups between olive cultivars.     

Study on Fruitset and Pollen-Compatibility Status in Sweet Cherry (Prunus avuim L.) Cultivars

Prunus avium L. is one of the most important temperate zone fruits in the world. Most of the cherry cultivars always have difficulties of fertilization and fruit set due to self-incompatibility, so they need suitable and compatible pollinizers for commercial fruit production. In this experiment, pollination compatibility of cherry cultivars of ‘Napoleon’, ‘Burlat’, ‘Zhan’, and ‘Lambert’ was studied as both pollen recipients and donors. To determine the compatibility or incompatibility of pollinizers, percent of fruit set was calculated. This research was carried out as a factorial experiment in a randomized complete block design. The final average fruit set in studied cultivars was different under self or cross-pollination. The results showed that ‘Napoleon’, ‘Zhan’ and ‘Lambert’ cultivars are the suitable pollinizers for ‘Burlat’. Also, ‘Burlat’ is a cultivar which produced many fruits under self-pollination. Therefore, ‘Burlat’ can be used as monoculture for orchard establishment. Results showed that cultivar ‘Napoleon’ was cross-incompatible with ‘Lambert’. ‘Zhan’, ‘Napoleon’ and ‘Lambert’ cultivars are founded self-incompatible and require cross-pollinations to obtain fruits.

     

高温胁迫对孔雀草和万寿菊不同品种生长和生理的影响

以万寿菊属（Tagetes）的6个孔雀草品种和3个万寿菊品种为试材,研究了38℃／21℃（昼／夜）高温胁迫对其株高、根长、根数、干样质量、热害指数以及叶绿素[Chl．（a＋b）]含量、叶片相对电导率（REC）、丙二醛（MDA）含量、叶片相对含水量（RWC）、抗氧化酶（SOD、POD、CAT、APX）活性等指标的影响。结...     

Studies with ethephon for facilitating olive harvest

Three olive cultivars under different irrigation regimes — irrigated ‘Manzanillo’, non or supplementary irrigated ‘Suri’ and non-irrigated ‘Nabali’ — were treated with ethephon to loosen the fruit for conventional or mechanical harvesting. For all cultivars, concentrations in the order 1 500 ppm were satisfactory and increased the efficiency of both mechanical and manual picking. In most cases at higher concentrations leaf drop increased and flower bud differentiation decreased considerably. The wetting agent Regulaid was a more effective additive than Triton X100 or calcium nitrate (0.3 M). Morning sprays were more effective than those given at noon, as were also sprays in the coastal plain when compared to the dry and hot inland valley.     

Growth,development and mineral contents of three cultivars of amarant

The growth, development and mineral contents of 3 cultivars of amarant (Amaranthus cruentus L.), ‘Large Leaf’, ‘Light Red’ and ‘Local Green’, were compared in a greenhouse study. There were small differences between the cultivars for the development per plant of leaf area, number of branches, number of nodes, and dry-weight production of stems, roots, inflorescences and most especially leaves at the edible stage. The 3 cultivars produced edible shoots between 5 and 7 weeks. There were, however, significant differences in the mineral content of the cultivars, in the order ‘Local Green’ > ‘Large Leaf’ > ‘Light Red’, for the concentrations of nitrogen, calcium, magnesium, iron and manganese. It is concluded that, although the 3 cultivars matured at the same time, ‘Local Green’ was the most nutritive as to mineral contents.     

Apoplastic anti-oxidants in pepper (Capsicum annuum L.) fruit and their relationship to blossom-end rot

Summary

The aim of the present research was to study changes in the major anti-oxidative enzyme activities known to be associated with the apoplast, during the induction of blossom-end rot (BER) in bell pepper (Capsicum annuum L.) fruits grown under saline conditions. Pepper plants of the BER-sensitive cv. ‘Mazurka’ and less-sensitive cv. ‘Selica’ were grown under control, low- and high-salinity irrigation regimes. Fruits were harvested continuously and, after approx. 7 months under these conditions, BER symptoms started to appear (in the Spring season) and fruits were sampled for biochemical measurements. The intercellular washing fluid (IWF; apoplast fraction) of the fruit pericarp was prepared and enzyme activities in that fraction were determined. The results showed that production of reactive oxygen species (ROS) in the fruit apoplast was higher in ‘Mazurka’ than in ‘Selica’. Apoplastic peroxidase and superoxide dismutase (SOD) activities, and the concentration of ascorbic acid, increased during ‘Selica’ fruit development, whereas the concentration of H₂O₂ decreased. During the stage of rapid growth, when fruits are most susceptible to BER, apoplastic peroxidase activity was greatly enhanced in the healthy pericarp of BER-affected fruits compared to healthy fruits. Under saline conditions, apoplastic peroxidase and SOD activities, as well as ascorbic acid and H₂O₂ levels, increased in healthy fruits of the resistant cultivar ‘Selica’; whereas, in healthy fruit of the BER-sensitive cultivar ‘Mazurka’, apoplastic peroxidase activity decreased while the level of ascorbic acid increased, but to a much lesser extent than in ‘Selica’. SOD activity and H₂O₂ levels increased similarly in both cultivars with increasing levels of salinity. It is proposed that apoplast-associated peroxidase activity and ascorbic acid concentration are increased coordinately in response to salt stress and may be part of a protective anti-oxidation mechanism that determines cultivar sensitivity to BER.     

English walnut fruit growth and development

Samples of the ‘Ashley’, ‘Hartley’ and ‘Franquette’ cultivars of English walnut (Juglans regia L.) were collected at weekly intervals from bloom to harvest, and development of the fruit, embryo and surrounding tissue was followed. The first division of the zygote occurred approximately one week after pollination, by which time the endosperm, nucellus and integument had shown considerable growth. The endosperm first formed cell walls at the 8-celled embryo stage and was completely cellular by the time the embryo contained approximately 64 cells. Rapid growth of the cotyledons started as the shell began to harden at Week 7. Measurement of fruit growth indicated that fresh weight gain in ‘Ashley’ and ‘Hartley’ fruits followed a double sigmoid pattern, characterized by a 3-week period of slowed growth that began approximately 7 weeks after bloom. Rate of increase in total length and diameter also slowed greatly at Week 7. Fresh weight gain in ‘Franquette’ appeared to follow a single sigmoid curve, with no prolonged period of slowed growth corresponding to that in the other cultivars. Kernel growth also described a double sigmoid curve, with its initial, rapid phase nearly coincident with the beginning of Stage III of the whole-fruit, fresh-weight curve at Week 10.     

秋子梨野生种和部分栽培品种交配亲和性研究

以秋子梨(Pyrus ussuriensis Maxim.)为试材,进行了花粉育性和交配亲和性研究。结果表明,参试的32份资源中有53%为雄性不育类型,可育品种间的花粉生活力存在明显差异,人工催花的花粉生活力低于自然开花,但对授粉结实无显著影响。南果梨、苹香梨、寒香梨等大部分栽培品种及山梨5个株系(野生秋子梨)都表现为自交不亲和。红花盖梨花期自交能够结实,但所结果实的种子不正常,为假亲和。龙香梨有一定自交结实力,花期人工自交花序坐果率达23.3%。部分具有自交不亲和性的梨品种蕾期自交授粉可提高结实率,但盛花后期授粉无显著影响。梨子代品种与亲代间互交,大部分组合表现亲和。南果梨×寒红梨组合交配亲和,但反交不亲和。梨同一类型不同品种间杂交结实正常,但亲本与其芽变品种间交配不亲和。     

Studies on the Nutrition of Tulips and Narcissi

Summary

We explored the effects of pollination method (hand cross-, hand self-, automatic self-, and open-pollination) and pollen source on fruit set and growth in four red-skinned pitaya (Hylocereus spp.) cultivars [‘Vietnam White’ (‘VNWhite’), ‘Chaozhou 5’, ‘Orejona’, and ‘F11’] in Taiwan.‘VN-White’ has white flesh, while the other three cultivars have red flesh. There were no significant differences in pollen viability or germination rate among the four cultivars, irrespective of whether the pollen was collected at night (approx. 20.30 h) or on the following morning (approx. 08.30 h).The results also indicated that ‘VN White’ was fully self-compatible and exhibited a high fruit set percentage (80 - 96%) following all pollination treatments. This cultivar produced the largest fruit from both hand self- and openpollination, compared to the three other cultivars tested. ‘Chaozhou 5’ was partly self-compatible, and ‘Orejona’ and ‘F11’ were completely self-incompatible. Hand cross-pollination significantly increased the fruit set percentages and mean fruit fresh weights (FWs) in ‘Chaozhou 5’ and ‘Orejona’. Pollen source also significantly affected the fruit set percentage and fruit FW. ‘VN-White’ (after self-pollination) and ‘Chaozou 5’ (after crossing with ‘VN-White’) gave superior fruit set percentages and fruit FWs. Reciprocal crosses between ‘Orejona’ and ‘F11’ also resulted in high fruit set percentages as well as large fruit in both cultivars. Therefore, the source of pollen and the method of pollination can affect fruit production in some cultivars of pitaya. Self-compatibility in ‘VN-White’ concurs with the morphology of its flowers in which the anthers lie in close proximity to the stigma.The distance between the anthers and the stigma may be used an indicator of whether hand pollination is necessary for a pitaya cultivar.     

Cloning of the S25 cDNA from ‘McIntosh’ apple and an S25-allele identification method

Summary

An S₂₅-RNase gene in the pistil responsible for self-incompatibility within the apple (Malus × domestica Borkh.) was cloned from a McIntosh cultivar. We developed an S₂₅-allele-specific polymerase chain reaction and digestion (PCR-digestion) method using specific primers and the restriction enzyme BamHI. We investigated the S-allele genotypes of 18 ‘McIntosh’ progeny.     

马铃薯脱外壁花粉的制备与人工萌发

 将3个马铃薯普通栽培种( Solanum tuberosum L. ) ‘陇薯3号’、‘Favorita’和‘Shapody’的花粉先经低温饥饿处理, 再低温水合、高温热激和渗激, 分离出大量具有活力的脱外壁花粉, 花粉最高脱壁率达34.5%。脱外壁花粉在K₃ 培养基+ 15% PEG + 5%蔗糖+ 0.01% H₃BO₃ + 0.01% LH + 100mg/L PVP的萌发液中萌发率高达38.3%。试验建立了三步冲击法制备马铃薯脱外壁花粉的方法, 并讨论了外壁在花粉萌发与受粉中的生物学意义。     

Pistil abortion is related to ovary mass in olive (Olea europaea L.)

Pistil abortion is considered to be an evolutionary adaptation to save resources in andromonoecious species, balancing the number of pistils with the resources available. It follows that large-fruited species/cultivars should have greater levels of pistil abortion. Working in olive, we found that pistil abortion, expressed as percentage of staminate flowers, was positively correlated to the average ovary mass at bloom, across cultivars with different ovary/fruit mass. Since ovary mass correlated with fruit mass, pistil abortion also correlated with fruit mass. The absolute number of perfect flowers per inflorescence was negatively correlated with both ovary mass and pistil abortion, while the number of staminate flowers per inflorescence increased with both parameters. The total number of flowers (i.e. staminate + perfect) was not correlated to ovary mass or pistil abortion, suggesting that male function was not affected. The results support the hypothesis that pistil abortion is related to competition for resources among ovaries, and suggest that genetic differences in pistil abortion among olive cultivars may be explained by their different pistil mass and sink strength.     

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.     

中国原产果梅自交亲和变异品种花粉决定基因SFB的插入突变

 果梅是配子体自交不亲和树种,但在长期进化过程中也出现了自交亲和品种。以果梅典型的自交不亲和品种‘南高’和自交亲和品种‘甲州小梅’为对照,采用田间自交授粉试验对原产于中国的‘四川白梅’和‘长农17’两个果梅品种进行了自交亲和性鉴定,结果表明：其自花授粉坐果率分别为30.73%和16.27%,属于自交亲和品种。进一步通过AS-PCR分析发现花粉SFB基因存在一段插入序列,造成了分子水平的基因突变。推测该基因的突变使‘四川白梅’和‘长农17’SFB功能发生改变,从而自交亲和。     

In vitro germination of apple pollens

In order to characterize pollen viability and germinability by biochemical parameters, an introductory investigation was made of the germinability in vitro of pollen of 2 apple cultivars, ‘Golden Delicious’ and ‘Starkrimson’, partially self-incompatible and totally self-incompatible, respectively. Best results of percent germination were obtained for both cultivars after 120 min incubation in Petri dishes at 30°C in a medium containing 0.2 M sucrose, 20 μg/ml H₃BO₃, 300 μg/ml Ca(NO₃)₂ · 4H₂O. Optimum pH was 6.0 for ‘Starkrimson’ and 7.0 for ‘Golden Delicious’.     

Magnesium deficiency induced oxidative stress and antioxidant responses in mulberry plants

The aim of the study was to implicate induction of oxidative stress and antioxidative responses with the effects of Mg deficiency in mulberry plants. Mulberry (Morus alba L.) cv. Kanva-2 plants grown in hydroponics were subjected to deficiency of Mg. Mg-deficient plants developed visible symptoms—deep interveinal chlorotic mottling and necrosis in the older and middle leaves. The decreases in the dry matter yield of plants and concentrations of sugars and starch in the leaves of Mg-deficient plants are suggestive of decreased photosynthetic activity. Mg-deficiency decreased concentrations of photosynthetic pigments, and increased concentrations of H₂O₂ and ascorbate and activities of antioxidative enzymes—peroxidase (POD), ascorbate peroxidase (APX) and superoxide dismutase (SOD). The results suggest induction of oxidative stress by enhancing generation of ROS and inducing alterations in redox status, accompanied by activation of antioxidant machinery including induction of some new SOD isoforms in Mg-deficient mulberry plants. Despite significant increase in H₂O₂, lipid peroxidation was decreased in Mg-deficient plants.