Hemiptelea mikii sp. nov. (Ulmaceae), fossil fruits and woods from the pleistocene of central Japan

A new fossil species,Hemiptelea mikii, is described on the basis of fruits from the Pleistocene of central Japan. It is distinguished fromH. davidii, the only extant species of the genus restricted to Korea and China, in having shorter fruits. Fossil woods discovered from the same horizon differ from the extant one in some anatomical characteristics, and are assigned to the new fossil species. Taken together with earlier records of fossil fruit occurrence in the early and the middle Pleistocene of central Japan, the latest finding of fossil fruits and woods from the last glacial sediments (ca. 50,000 years ago) at Kita-egota site of Tokyo suggests thatH. mikii was widespread in central Japan throughout the Pleistocene and survived until as late as the Last Glacial age.     

Control and manipulation of gene expression during tomato fruit ripening

Ripening is a complex developmental process involving changes in the biochemistry, physiology and gene expression of the fruit. It is an active process characterised by changes in all cellular compartments. cDNA cloning has been used as an approach to analyse changes in gene expression during fruit ripening. This has revealed that several genes are switched on specifically during fruit ripening, including one encoding polygalacturonase (PG), a major cell wall protein. These cDNA clones have been used to study the expression of the genes in normal and ripening mutant fruits, and under environmental stress conditions.The PG gene has been isolated and it has been demonstrated that 1450 bases 5 of the coding region are sufficient for the tissue- and development-specific expression of a bacterial marker gene in transgenic tomatoes. Antisense RNA techniques have been developed to generate novel mutant tomatoes in which the biochemical function of this enzyme and its involvement in fruit softening has been tested.     

Somatic embryogenesis from seed explants of Abies alba

Megagametophytes of Abies alba containing the immature embryos were dissected from the seed coats and divided by longitudinal and transverse sections. They were placed with the cut surface down on modified Schenk & Hildebrandt medium containing 50 mgl^-1 myo-inositol and 2% sucrose, supplemented with 1 mgl^-1 N⁶-benzyladenine (BAP). An embryogenic type of callus proliferated after one month of culture. Closer examination revealed the presence of structures resembling early stages of embryogenesis as well as of single elongated, vacuolated cells and clusters of cells with dense cytoplasm. Under appropriate conditions, some of the somatic embryos elongated and formed cotyledons.     

温州蜜柑果实生长动态特征及影响因子的分析

金衢盆地柑桔生产历史悠久。近10年来发展很快,已形成浙江第二个柑桔产区。由于受东亚季风气候影响,该区柑桔不但冬季易遭冻害,而且夏秋易受高温干旱危害,冬季的低温冻害和夏季的高温干旱是造成桔柑减产的两个主要     

乙烯对番茄成熟过程中果皮细胞核超微结构的影响

应用冰冻蚀刻和透射电镜观察了番茄成熟过程中果皮细胞核染色质的变化。成熟过程开始启动时(发白期),异染色质不断减少、分散,直至转色成熟。果实成熟衰老时细胞核形态畸变,染色质结构瓦解。经外源乙烯处理后果实成熟加速,异染色质减少,核孔数量增加,NBD可消除乙烯的作用。     

The wide but disjunct range of the European mountain plant Androsace lactea L. (Primulaceae) reflects Late Pleistocene range fragmentation and post‐glacial distributional stasis

Aim Our aim was to reconstruct the spatio‐temporal genetic diversification of Androsace lactea, a widely but disjunctly distributed European mountain plant, to test the hypothesis that its distribution is the result of vicariance, in the late Tertiary or during the Pleistocene, or alternatively of long‐distance dispersal. We also addressed the phylogeographic history of the Alps, emphasizing the role of Pleistocene refugia at their northern margin. Location The central and southern European mountain ranges. Methods We gathered amplified fragment length polymorphism (AFLP) data and plastid DNA sequences from one to four individuals of each of 26 populations spanning the entire distribution area. AFLP data were analysed with Bayesian clustering approaches, neighbour‐joining analysis and NeighbourNet. Plastid sequences were used to depict relationships among haplotypes in a statistical parsimony network, to test for population expansions, and to obtain age estimates in a Bayesian framework. Results The AFLP data suggested that many populations were genetically strongly differentiated. The internal structure, however, was weak, and only two major groups of populations, from the north‐western Alps and adjacent regions and from the easternmost Alps, were supported in the neighbour‐joining analysis. One of the Bayesian clustering approaches differentiated three groups of populations: Northern Alps, easternmost Alps and the remaining distribution area. Eleven closely related plastid haplotypes were found, separated by maximally four mutational steps, resulting in a star‐like parsimony network. None of several estimators suggested statistically significant population expansions. The diversification age was inferred to be (mean/median) 0.135/0.08 Ma (95% highest posterior density interval 0.364–0.006 Ma). Main conclusions We found no evidence that long‐distance dispersal shaped the disjunct distribution range; our data rather favoured a vicariance scenario. However, in contrast to the hypothesis that wide but disjunct distributions are old, we conclude that range fragmentation probably happened in the Late Pleistocene, perhaps during the last glaciation. In the Alps, most populations are at least close to formerly unglaciated areas. Our data support distributional stasis and suggest that important refugia were situated at the north‐eastern, but also at the northern and north‐western edges of the Alps, thereby strengthening the evidence for glacial refugia in this strongly glaciated region.     

Flower and fruit volatiles assist host‐plant location in the Tomato fruit fly Neoceratitis cyanescens

Mature females of the tomato fruit fly Neoceratitis cyanescens can detect host fruit at a short distance using only visual stimuli, but little is known about the role of airborne volatile cues in the host searching strategy. A series of experiments is conducted in a laboratory wind tunnel, in which the behavioural responses of individual flies to volatiles from Solanaceae host plants (including tomato Lycopersicum esculentum Mill., bug weed Solanum mauritianum Scop. and Turkey berry Solanum torvum Sw.) are observed, according to some environmental (air speed) and physiological (age and mating status of females, time of day) factors. Mature females respond primarily to specific olfactory cues from blends of flowers or host fruit, preferentially unripe fruit for bug weed, as opposed to ripe fruit for Turkey berry or tomato. Males are also highly attracted by the odour of unripe fruit of bug weed. Wind plays a key role, as shown by the proportion of flies that reach the upwind section of the tunnel in the presence of both fruit odour and air flow (66.7%) and in the absence of either fruit odour (13.3%) or wind (36.7%). In response to fruit volatiles carried by wind, flies embark in a ‘plume tracking’ or ‘aim and shoot' flight, consistent with odour‐conditioned anemotaxis. Females respond to host fruit odour regardless of their age, egg load or mating status, and also more consistently in the afternoon, which is their preferential time of day for egg‐laying. Searching behaviour and response to host volatiles in N. cyanescens are discussed in the light of host‐finding and an adaptive strategy.     

The effects of different blend ratios and temperature on the active space of the Oriental fruit moth sex pheromone

Abstract The wing-fanning activation response of male Oriental fruit moths (OFM), Grapholita molesta (Busck), in the field to the three-component pheromone containing the female-produced ratio of components (Z8-12:OAc + 6% E8-12:OAc + 3% Z8-12:OH) was compared with the response to blends containing 2,10 and 20% E with 3% OH, and the 6% E blend containing 30 and 100% OH. Comparisons were made over three temperature ranges: 15–17, 20–21 and 26–28^oC. Both the maximum response distance and male response specificity were significantly altered by changes in odour quality as well as temperature. For blends containing different Z/E ratios the maximum response distance increased significantly with temperature. Response specificity was most pronounced at the 20–21^oC range, with males displaying a lower threshold for the natural 6% E ratio, evidenced by the fact that fewer males responded and at closer distances to the source with off-ratios. At 26–28^oC response specificity for the Z/E ratios was much reduced, primarily due to more males activating to off-ratios. With blends containing different proportions of Z8-12:OH in the 6% E blend, increasing temperature increased the maximum response distance for all treatments, but in addition increasing the proportion of OH alone from 3% to 30% significantly increased the maximum response distance over the three temperature ranges tested. This increase occurred without affecting the proportion of responders or the distribution of response distances around the mean value. However, with 100% OH added to the blend, whereas male response was high at 20–21^oC, the distribution of response distances was significantly more variable than with 3% or 30%, and male response was eliminated or very low at 15–17^oC and 26–28^oC. Our results support previous studies showing that peak response levels in this species are dependent on male perception of the natural blend of components, and that males have a high degree of specificity for the qualitative properties of the pheromone. However, the present results also extend those of previous flight tunnel tests in which response specificity was most pronounced in the upwind flight phase of the sequence, by showing that male OFM also display a