Das Platzen von Weinbeeren (Vitis vinifera) bei Befall mit Grauschimmel (Botrytis cinerea)

Rain-cracking of post-veraison grape berries (Vitis vinifera L.) reduces yield and quality of must and wine. Under vineyard conditions, cracking is often associated with bunch rots. The objective of the present study was to identify the role of Botrytis cinerea Pers.: Fr. as the dominant bunch rot fungus in cracking of Riesling berries. For these experiments grape berries with characteristic symptoms of Botrytis infections were selected in the vineyard. Berries infected by Botrytis always cracked in those regions of the berry where symptoms of the infections (brownish purple colour of the fruit skin) were present. In 55 % of these berries, cracks were orientated perpendicularly to the pedicel/stylar scar axis. Microscopic cracks referred to as microcracks were often present in the stylar scar region and occasionally in the vicinity of lenticels. These cracks allowed penetration of the fluorescent tracer acridine orange. The area infiltrated by the dye was positively related to crack length (r²?=#x003D;?0.43*). Water uptake of detached berries increased with time. Rates of uptake were highly variable and higher for infected berries as compared to berries without infections. Rates of water uptake into infected berries were positively related to cumulative crack length (number of cracks multiplied with average crack length) per berry (r²?=#x003D;?0.45*). Exposing the outer surface of the strained grape berry exocarp to water increased the frequency of microcracks. The increase was larger in infected berries than in those without symptoms. Our data demonstrate that Botrytis infections increase the cracking susceptibility of Riesling grape berries by weakening the grape berry exocarp, increasing crack length per berry which in turn resulted in increased water uptake.     

蔬菜斑潜蝇的发生与防治

阐述了斑潜蝇的危害及其在我国分布的种类，对番茄斑潜蝇、美洲斑潜蝇及其防治作了详细论述。     

Variation in modulus of elasticity (E) along Acer platanoides L. (Aceraceae) branches

Arborists and managers of amenity trees could benefit from an improved understanding of how tree canopies withstand loading events such as wind, snow or ice. Knowledge of how material properties change along tree branches is important in understanding how a branch tips can bend in the wind yet resist displacement at the base which could lead to branch failure. Limited knowledge of modulus of elasticity (E or stiffness) in branch wood is available in the literature and is typically measured at only one location on a branch. This study investigated variation of E and density-specific E (E/ρ) at five locations along the axis of 20 branches from seven trees. E and E/ρ were found to be 70% lower at the branch tips than in the proximal locations. The variation in E was negatively correlated with the percentage of tissue area composed of vessels and positively correlated with mean fiber cell wall size, suggesting a balance between the two principle functions of hydraulics and mechanics. Reaction wood was observed in the form of gelatinous layers in fibers along the branch tops, but did not result in a difference in E between the top and bottoms at each branch location. It is proposed that differences in material properties are probably related to wood development type, as juvenile wood is considered to have lower stiffness than mature wood.     

Studies on sulphur nutrition and flavour production in watercress (Rorippa nasturtium-aquaticum (L) Hayek)

The effects of sulphate nutrition on watercress were investigated with respect to visual deficiency symptoms, growth response and flavour content as determined by sensory and gas-chromatographic methods. The plants were grown in a glasshouse, both in solution culture using plants propagated vegetatively and in sand culture using plants raised from seed, at six concentrations of sulphate in the nutrient medium. The two methods were complementary and led to substantially similar conclusions. There were steep increases in weight per plant, sulphur content and flavour strength with initial increases of sulphate concentration in the nutrient medium, followed by levelling off^- at the highest sulphate concentrations. Sulphur requirements for maximum growth were satisfied at lower sulphate concentrations (0.20-0.25 meq/1) than those for maximum flavour development (0.75 meq/1).

There is evidence that watercress flavour consists of at least two types of components: (a) components which impart a bland, generalized vegetable taste and odour and (b) a specific component or components which are perceived as a burning sensation in the mouth accompanied by a characteristic odour. Production of the former is independent of sulphur nutrition. Enzymatic production of ß-phenylethyl isothiocyanate from the corresponding glucosinolate is believed to be responsible for the latter. There were highly significant correlation coefficients between the isothiocyanate content of fresh tissues and their total and organic sulphur contents.

The possibility of controlling watercress flavour in commercial production, with a view to meeting consumer preferences, is briefly discussed.     

Identification of drought-induced genes from the leaves of Rangpur lime (Citrus limon (L) Osbeck)

Water stress is one of the limiting factors for citrus production and Citrus species show great variation in their response to drought stress. Although the majority of Citrus rootstocks are sensitive to water stress, Rangpur lime (Citrus limon (L) Osbeck) (RL) shows a high degree of drought tolerance. Therefore, it has been used as a rootstock in drought-prone environments, but mechanisms of drought tolerance are not yet known. In this study, to explore the mechanisms of drought adaptation and tolerance, a subtractive cDNA library was constructed from the leaves of 14-day drought-stressed and non-stressed RL for identification of drought-induced genes. 285 cDNA sequences were obtained from randomly selected clones from the subtracted library containing the drought-induced genes. The expression analyses of 200 cDNAs in 14-day drought treated and untreated RL by macroarray hybridisation revealed that the expression of 56 cDNAs increased two to 11-fold. 30 non-redundant drought-induced genes were identified from these cDNAs and drought induction of eight selected genes was confirmed by a real-time RT-PCR assay suggesting that expressions of these genes were regulated by drought-stress. Genes identified in this study were mostly related with cell rescue and defense pathways involved in drought adaptation and tolerance of RL.     

Syrian pear (Pyrus syriaca) as a pollinator for European pear (Pyrus communis) cultivars

In Israel four European pear cultivars are grown: ‘Spadona’ is the main cultivar and ‘Coscia’, ‘Gentile’ and ‘Spadochina’ are its pollinators. However, molecular S-genotyping revealed that ‘Spadona’ is semi-compatible with its three pollinators. This explains, at least in part, the relatively low pear yield in Israel. The Syrian pear (Pyrus syriaca) grows wild in Israel and blooms intensively, overlapping the blooming of the cultivated European pears. Cross-fertilization between Syrian pear and ‘Spadona’ was shown to be efficient suggesting that Syrian pear might be a potent pollinator for ‘Spadona’. Twenty-six Syrian pear seedlings, from different sites in north-east Israel were S-genotyped identifying 11 that are fully compatible with the four European pear varieties cultivated in Israel. By this screening, 24 different S-RNases were cloned; ten of them are new, whereas the other fourteen had been identified previously. In addition, seedlings of two wild pear species were also S-genotyped. Two seedlings from Pyrus betulifolia and one from Pyrus korshinskii were found to be genetically compatible with the four European pear cultivars. From these seedlings four S-RNases were cloned, two are new, one had been cloned previously and one was identical to an S-RNase allele cloned from Syrian pear in this work.     

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.     

几种杀虫剂及其混配对瓜实蝇成虫的毒力测定

采用微量点滴法,测定了毒死蜱、甲维盐、敌敌畏、顺式氯氰菊酯等4种杀虫剂对瓜实蝇成虫的毒力和二元混配的联合毒力。结果表明：80 %敌敌畏乳油（EC）的LD50最小,为1.683 9 μg?g-1|100 g?L-1顺式氯氰菊酯EC的LD50最大,为8.877 0 μg?g-1。供试杀虫剂毒性大小依次为：80 %敌敌畏EC＞5 %甲维盐微乳剂（ME）＞480 g?L-1毒死蜱EC＞100 g?L-1顺式氯氰菊酯EC。敌敌畏与甲维盐（1∶1）混配的增效作用最强,共毒系数为426。     

Effect of harvest stage and processing treatment on the quality of sun dried ker ( Capparis decidua) (Forsk) Edgew) fruit

Summary

Ker fruit harvested at three stages (immature, semi-mature and fully-mature) were subjected to different processing treatment viz., blanching and curing. Then the fruit were sun dried and stored for six months to study their quality. Fruit harvested at an immature stage (20.d after fruit set) and blanched for 3 min followed by curing in salt (5%) for the first 6.d and salt 10% + buttermilk 25% for the next 6.d proved significantly superior in terms of better rehydration ratio, ascorbic acid content and organoleptic quality.     

樱桃叶片对PP333吸收、运转及分配规律的研究

利用~(14)C的同位素示踪技术,结合观察定位施用PP333后樱桃植株营养生长的反应,研究了樱桃叶片对PP333的吸收、运转及分配规律。试验结果表明,叶片不仅能大量地吸收药物,而且可以大量地迅速向外运转,8天中吸收量和运转量分别占施用量的87.7%和81.8%。吸收量和运转量的变化与时间的相关均为高度的渐近曲线相关,相关方程分别为:Y=93.0-84.8(0.987)~x和Y=86.0-79.1(0.986)~x。     

Pollinator selection in kiwifruit (Actinidia deliciosa)

SUMMARY

Pollinator performance was evaluated in kiwifruit to select pollinators for cv. Hayward adapted to the cultural conditions of southern Europe. Flowering time was determined in forty male seedlings. From, these, nine were selected for having a flowering period overlapping with ‘Hayward’. In these nine males, as well as in the commercial pollinators‘Matua’ and Tomuri’, the production of pollen was studied over two years, investigating pollen quantity through flower density and pollen production per flower. Likewise, in vitro pollen viability and its in vitro germination were recorded to study pollen quality. Finally, in vivo pollen performance was studied through fruit set and fruit characteristics in controlled hand pollinations. Two males have been selected with a flowering period coincident with ‘Hayward’, which produce more than twice as much germinable pollen than commercial pollinators. Whilst there were no significant differences in pollen quality or in fruit production, clear differences existed for pollen quantity in terms of both flower density and pollen production per flower. As pollen quantity, together with flowering time, can be easily evaluated at an early stage, this is encouraging for future selection ofkiwifruit pollinators.     

Improving disease resistance in peach fruit during storage using benzo-(1,2,3)-thiodiazole-7-carbothioic acid S-methyl ester (BTH)

Summary

The compound benzo-(1, 2, 3)-thiodiazole-7-carbothioic acid S-methyl ester (BTH) effectively induces a systemic acquired resistance (SAR) response in plants and increases plant resistance to disease. To learn how BTH may affect post-harvest quality and disease resistance in peach, (Prunus persica L. cv. ‘Jiubao’) peach fruit were treated with 200 mg l^–1 BTH for 5 min immediately after harvest, then incubated for 60 h at 20°C, 85–95% RH. Sixty h after treatment, fruit were inoculated with spore suspensions of Penicillium expansum at 1.2 10⁴ CFU ml^–1. The incidence of disease and lesion areas on peach fruit were significantly reduced by BTH-treatment (P < 0.05). In addition, chitinase and -1,3-glucanase activities in peach fruit were significantly enhanced by BTH-treatment (P < 0.05). Moreover, the total levels of phenolic compounds and chlorogenic acid, and the lignin content of BTH-treated fruit were significant higher than in control fruit (P < 0.05). The effects of BTH on fruit quality were also analysed. Soluble solids content, soluble pectin, titratable acidity and ascorbic acid levels in peach fruit were not significantly affected by treatment with BTH. Our results suggest that the application of BTH may control post-harvest diseases in peach fruit during commercial production.     

Genetic relatedness (diversity) and cultivar identification by randomly amplified polymorphic DNA (RAPD) markers in teasle gourd (Momordica dioica Roxb.)

Genetic relationship and variation of 29 accessions of teasle gourd (Momordica dioica Roxb.) and 1 accession of Momordica cochinchinensis Spreng. (wild relatives of teasle gourd) were examined by RAPD analysis using 44 dodecamer oligonucleotide primers. A total of 496 fragments were produced by 44 primers of which 95% bands were polymorphic. Using presence or absence of specific RAPD markers or combination of primers, 23 out of 30 accessions were identified. The genetic relatedness or genetic distance based on Nei and Li's genetic similarity varied from 0.86 to 0.65 with an average of 0.74 among 29 M. dioica accessions (when M. cochinchinensis excluded). In the phenetic dendrogram developed from cluster analysis using UPGMA method, M. cochinchinensis was out grouped as single accession, while others showing relatively weak grouping formed four groups. Clustering pattern did not demonstrate any relationship between geographical origin and genetic diversity. A DNA extraction method has been standardized. This is the first report of using RAPD techniques in teasle gourd. It was concluded that RAPD analysis is a useful tool for genotypic identification and estimation of genetic similarity in teasle gourd.     

Salt Tolerance of Lentil (Lens Esculenta)

Lentil plants of the Beladi type were grown at various NaCl levels under laboratory, greenhouse and field conditions with the object of determining the salt tolerance limits. Salt tolerance was much higher during germination than during subsequent growth. A 50% reduction in germination occurred at about 20.0 mmhos cm^-1. Seed yield was reduced to 50% at soil salinity of about 3.9 mmhos cm^-1. Plant survival, pod formation and seed quality were adversely affected by higher salt levels. Total nitrogen in the kernel decreased with rising soil NaCl levels while that of the husk increased.     

甜瓜基因目录(2002)

2002年MichelPitrat在国际葫芦科遗传协会年报(CGCReport)第25期发表了最新的1份甜瓜基因目录1,它包括171个不同类型的基因。此译文是在1998年发表的基因目录2基础上增加了55个基因,其中包括8个QTL定位基因、1个细胞质基因。现将增加的基因全文整理翻译出来,供读者参考。     

化感物质己二酸二异丁酯对茄子黄萎病及幼苗生长的化感效应

 采用模拟的方法,研究了己二酸二异丁酯对茄子黄萎菌及茄子种子萌发、幼苗生长的化感效应。结果表明,己二酸二异丁酯在黄萎菌培养的前阶段极显著地抑制了菌丝的生长,培养7 d时,1.0 mmol·L^-1的抑制作用最大;11 d时,则促进了菌丝的生长,但未达到显著水平。田间抗病试验结果表明,各浓度己二酸二异丁酯均提高了茄子幼苗对黄萎病的抗性,其中以0.5 mmol·L^-1处理最好。己二酸二异丁酯低浓度时促进了茄子种子的萌发,增加了幼苗的株高、茎粗、地上和地下部干鲜质量、叶绿素含量和根系活力,而随着浓度增大,促进作用减弱或者表现出抑制作用。低浓度的己二酸二异丁酯对叶片丙二醛（MDA）含量和细胞膜相对透性起化感抑制作用,并随浓度增加作用强度增大;但浓度增至1.0 mmol·L^-1时,表现化感促进作用。     

Structural differences in wheat (Triticum aestivum), hemp (Cannabis sativa) and Miscanthus (Miscanthus ogiformis) affect the quality and stability of plant based compost

Physical properties as well as process parameters were examined in three different composts based on plant residues. The wheat compost was a mixture of clover-grass and wheat straw in a ratio of 3:5, the Miscanthus compost was composed of the same materials and contained Miscanthus straw in addition in a ratio of 3:2.5:2, and the hemp compost was based on clover-grass, wheat and hemp straw also in a ratio of 3:2.5:2. The wheat and Miscanthus composts both had an initial C/N ratio of 26 and process parameters such as nitrogen losses and mineralisation pattern did not differ between the two compost types. The hemp compost had a much lower initial C/N ratio of 16 as the hemp straw was harvested fresh, resulting in higher losses and more mineralised nitrogen during composting. Particle size distribution was determined by image analysis of scanned samples. No differences were observed between the percentages of particles in the selected length intervals, however, the largest number of particles was observed in the Miscanthus compost. Particles in the hemp compost had more uneven surfaces than the other composts and had the highest water retention capacity. Thus, the geometry and surface characteristics of the particles and the pores created are important in determining the suitability of plant based growing media.     

Male performance in pistachio (Pistacia vera)

Pollinator performance was evaluated in a collection of 17 male and 37 female pistachio clones from Cyprus, Greece, Iran, Israel, Syria, Tunisia and USA. Flowering time, pollen quantity and pollen quality were evaluated. The flowering dates of the clones spanned one month and covered the flowering time of the main female cultivars. Pollen quality, evaluated as in vitro pollen germination, was high in all the studied clones, averaging 85 %. However, big differences existed in pollen quantity, measured both as inflorescence density and as pollen per inflorescence. Thus, the amount of pollen per inflorescence averaged 173 mg and ranged from 73 mg to 252 mg. The fact that flowering time and pollen quantity were the two most variable characters between clones, but were constant over years, together with the fact that they are two characteristics easily measured in the nursery makes them good criteria for pollinator selection in this species.     

Volatile organic compounds in watermelon (Citrullus lanatus) grafted onto 21 local and two commercial bottle gourd (Lagenaria siceraria) rootstocks

Summary

Volatile organic compounds (VOCs) are responsible for flavour development in watermelon (Citrullus lanatus). The objective of this study was to investigate the rootstock effects of 21 local bottle gourd [Lagenaria siceraria (Molina) Standl.] accessions collected from the Mediterranean region (Turkey) on the concentrations of VOCs in watermelon over 2 years. The watermelon cultivar ‘Crimson Tide’ was used as the scion and two commercial bottle gourd rootstocks were also used for comparison. The VOCs in each rootstock-scion combination were analysed using static headspace (SHS) and gas chromatography-mass spectrometry (GC-MS). A total of 24 VOCs were identified in watermelon fruit, including 11 aldehydes, seven alcohols, four ketones, one heterocyclic compound, and one acid. Acetaldehyde (25.9 – 39.5% of the total peak areas), propanal (5.0 – 8.3%), 2-propanone (2.5 – 4.9%), pentanal (2.1 – 3.6%), hexenal (14.5 – 22.6%), (E)-2-hexenal (0.4 – 2.3%), 6-methyl-5-hepten-2-one (10.0 – 19.05%), nonanal (1.6 – 4.4%), (Z)-6-nonenal (4.0 – 9.8%), (E)-2-nonenal (0.6 – 2.0%), (E,Z)-2,6-nonadienal (2.1 – 3.7%), (Z)-6-nonenol (1.0 – 3.2%), and (E,Z)-3,6-nonadienol (1.0 – 3.7%) were the most abundant VOCs found in all watermelon scions. There was no significant effect (P ≥ 0.05) of rootstock on the concentrations of acetaldehyde, propanal, pentanal, heptanal, ethanol, 1-pentanol, 2-propanone, 2-pentyl furan, or acetic acid. Propanal, 2-propanone, and acetic acid were identified as VOCs in watermelon for the first time. Hexanal, (Z)-6-nonanal, and 6-methyl-5-hepten-2-one concentrations were strongly affected by rootstock. The results showed that the local bottle gourd accessions 07-06 and 31-09, in particular, were the most promising genotypes in terms of producing favourable VOCs. Except for the local bottle gourd accessions 33-35, 01-17, and 07-04, the other 18 gourds accessions had high potential as rootstocks for breeding programmes in watermelon with regard to desirable VOC concentrations. Rootstock 31-09 should be considered for commercial production in terms of improved disease resistance, fruit yield, and fruit quality.     

Improvements in somatic embryogenesis protocol in Feijoa (Acca sellowiana (Berg) Burret): Induction,conversion and synthetic seeds

Pineapple guava (Acca sellowiana) syn. Feijoa sellowiana, a Brazilian indigenous Myrtaceae is under domestication in South Brazil. Previous works showed that this species is responsive to somatic embryogenesis and recalcitrant to conventional methods of clonal propagation. In the present work it was evaluated the role of components of culture medium in the induction and development of somatic embryos. The technology of synthetic seeds was also evaluated. Zygotic embryos were inoculated in LPm medium supplemented with 8 mM glutamic acid and 8 mM l-glutamine, 2,4-dichlophenoxiacetic acid (20 μM) and myo-inositol. For conversion of somatic embryos and synthetic seeds it was tested the effect of 6-benzylaminopurine and gibberellic acid combined or not with activated charcoal. The highest values for embryogenetic induction (100%) and number of somatic embryos/explant (113) were observed in the LPm medium supplemented with Glu (8 mM), and 2,4-D. The culture medium supplemented with BA (0.5 μM) and GA₃ (1 μM) and activated charcoal (1.5 g L⁻¹) enhanced the conversion of somatic embryos to plantlets. Pre-germinated somatic embryos encapsulated in sodium alginate with BA (0.5 μM) and GA₃ (1 μM) developed radicles. The use of synthetic seed was a requisite for the survival of plantlets.