Growth characteristics and ion contents of non-selected and salt-selected callus lines of highbush blueberry (Vacdnium corymbosum) cultivars Blue Crop and Denise Blue

Non-selected and sodium chloride selected callus lines of Vacdnium corymbosum L.cv Blue Crop and cv. Denise Blue were grown on media supplemented with 0–100 mM NaCl. For both cultivars, fresh weight and dry weight yields were greater in selected lines on all levels of NaCl. Selected lines of Blue Crop displayed better growth than selected lines of Denise Blue at most concentrations of NaCl. Internal Na⁺ and Cl^– concentrations in selected and non-selected lines of both cultivars increased as external concentration was raised. However, selected lines of Blue Crop and Denise Blue accumulated more Na⁺ and Cl^– than non-selected lines. Selected lines of both cultivars maintained higher levels of K⁺ than non-selected lines on all external NaCl levels. Selected lines of Blue Crop had higher levels of Na⁺ and Cl^– than that of Denise Blue. The results suggest Na⁺ and Cl^– accumulation could be a mechanism allowing better growth in selected lines at moderate salinity levels (50–75 mM NaCl).     

越桔亚科植物化学成分研究进展

本文综述了近年来越桔亚科植物的研究进展。分别介绍了越桔属,红梅苔子属等化学成分研究的概况。     

Influence of irradiance on in vitro growth and proliferation of Vaccinium corymbosum (highbush blueberry) and subsequent rooting in vivo

The effects of light on in vitro proliferation and subsequent in vivo rooting and acclimatisation of Vaccinium corymbosum were investigated. The shoots were exposed in vitro to different irradiances (total radiation ranging from 55 to 240 μmol m⁻² s⁻¹) for 7 to 60 days. In vitro growth and proliferation and the possible consequences on in vivo rooting were observed.
As compared to the control treatment (55 μmol m⁻² s⁻¹), higher irradiances improved proliferation and rooting ratios only with short applications (7 days). Short but high (210 μmol m⁻² s⁻¹) exposures applied at the end of the proliferation phase increased in vivo growth and rooting of the shoots. The shoots treated with strong light for longer times (14 and 28 days) showed both inhibition of growth and red colour of leaves and sprouts, and were less vigorous when transferred in vivo.     

Sequential style removal in highbush blueberry,Vaccinium corymbosum L.: Effects on fertilization success and seed germination

Plants of the blueberry cultivar Bluecrop were pollinated with pollen from the cultivars Sierra and Duke under controlled conditions. After pollination, styles were removed at 6 h intervals from 1.25 days to 4.00 days. An increase in the number of developed seed was seen across time, ranging from 1 seed per fruit (s/f) at 1.25 days, to a peak of 63.4 s/f at 3.25 days in 1992, and from 0.1 s/f at 1.25 days to 56.0 s/f at 3.75 days in 1993. Germination tests of 200-seed seedlots of Bluecrop×Sierra exhibited a significant trend toward earlier germination by seed from earlier style removal times. Seed weight measured in the cross Bluecrop×Duke, however, showed decreasing weights with longer style removal times, suggesting that seed size may time of germination. A multiple regression of seed size and stylar removal time against time of germination showed that style removal time was the only significant source of variation for germination time. Results suggest that pollen vigor, as reflected in the speed of growth down the style, may have a direct bearing on characteristics of the seed and subsequent plant.     

The role of mycorrhizal infection in the tolerance of Vaccinium macrocarpon to iron

Hymenoscyphus ericae survived in liquid media containing up to 500 g/ml iron (Fe), Mycorrhizal seedlings of Vaccinium macrocarpon showed higher yields and lower shoot Fe levels and exhibited less severe toxicity symptoms than nonmycorrhizal seedlings.     

Host fruit chemical stimuli eliciting distinct ovipositional responses from sibling species of Rhagoletis fruit flies

Laboratory experiments tested whether two economically-important sibling species of tephritid fruit flies have evolved distinct egg-laying responses to chemical stimuli on the fruits of their respective hostplants. The egg-laying preferences displayed by apple maggot flies, R. pomonella, and blueberry maggot flies, R. mendax, on artificial fruits treated with apple and blueberry extract paralleled their egg-laying responses to whole apples and blueberries. R. pomonella flies laid more eggs than R. mendax flies in artificial fruits treated with extract from ripe McIntosh apples, and vice versa for artificial fruits treated with extract from ripe Bluehaven blueberries. Furthermore, both species laid more eggs in artificial fruits treated with extract from their respective host fruits than control artificial fruits which were not treated with fruit extract. Prior electroantennogram recordings from R. mendax and R. pomonella flies exposed to volatiles from pentane extracts of apples and blueberries indicate that the antennal sensitivity of both species is selectively tuned to their respective host fruit odors. This differentiation in their olfactory responses to fruit odors could be important in mediating their distinct ovipositional responses to blueberry and apple fruits. Extract from unripe McIntosh apples also elicited egg laying by R. pomonella flies, however, artificial fruits treated with unripe apple extract received 1.9 times fewer eggs than those treated with ripe apple extract. Moreover, the numbers of R. pomonella ovipositor punctures and eggs placed in wax artificial fruits were increased when the artificial fruits were treated with a blend of 7 identified apple esters. Black coloration on these artificial fruits and the presence of apple esters had a synergistic effect on the egg-laying behavior of R. pomonella flies, which caused them to lay substantially more eggs per black fruit than white fruit treated with the same concentration of apple esters. In summary, our results indicate that the egg-laying responses of R. pomonella flies are mediated by the integration of information from fruit chemical and visual cues, and that R. mendax and R. pomonella flies have evolved divergent egg-laying responses to chemical stimuli on the fruits of their respective hostplants. These findings are discussed in the context of other studies on plant compounds which influence the ovipositional behavior of phytophagous Diptera.

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Stimuli chimiques des pommes et des myrtilles induisant la ponte des espèces jumelles, Rhagoletis pomonella et R. mendax

Résumé Des fruits artificiels en cire traités avec des extraits de fruits ont provoqué chez les espèces jumelles de R. mendax (Curran) et R. pomonella (Walsh) des réactions de ponte différentes suivant les stimulations chimiques par les fruits. Le comportement de ponte sur des fruits artificiels traités avec des extraits au pentane des myrtilles mûres (Vaccinium corymbosum L.) et de pommes mûres (Malus pumila Miller = Pyrus malus L.), est le même que sur des fruits naturels, ce qui montre que la réponse aux stimulations chimiques provenant du fruit constitue un aspect important de la reconnaissance de l'hôte. R. pomonella pond plus d'ufs que R. mendax sur les fruits artificiels traités à l'extrait de pommes mûres; c'est l'inverse pour les fruits traités aux extraits de myrtille. Les fruits artificiels traités avec des pommes ou des myrtilles provoquent la ponte de R. pomonella, tandis que les myrtilles mûres seules provoquent la ponte de R. mendax. Les extraits de pommes vertes stimulent la ponte de R. pomonella mais elle est alors 2 fois plus faible qu'avec des extraits de pommes mûres. Un mélange de 7 esters identifiés dans l'extrait de pomme induit aussi la ponte de R. pomonella. Le nombre de piqûres de tarièresfli dans les fruits artificiels en cire et le nombre d'ufs par fruit ont été augmentés par addition d'esters de pommes à des fruits blancs ou noirs. La couleur des fruits artificiels influence aussi la réaction de ponte de R. pomonella; la fréquence des piqûres de tarière contenant un uf et le nombre d'ufs par fruit étaient significativement plus élevés sur les fruits noirs que sur les fruits blancs traités avec la même concentration d'esters de pomme. Les fruits artificiels noirs traités avec la concentration la plus stimulante d'esters de pommes ont reçu 2, 3 fois plus d'ufs que les fruits blancs avec les mêmes concentrations en esters. Ces résultats montrent que les esters de pomme et la couleur noire stimulent synergiquement la ponte de R. pomonella sur des fruits artificiels.