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1.
Sara Basconsuelo Herminda Reinoso Eugenia Lorenzo Rubén Bottini 《Plant Growth Regulation》1995,16(2):113-119
Morphological studies were carried out with peach flower buds collected monthly in 1989 and 1990, from two months before leaf fall (7 March) until two to three weeks before bloom (7/8 August). Chilled (2–4°C for 30 days) and unchilled buds were exposed to 20 to 25°C, 100% RH and continuous light. Gibberellin A3 (3 ng or 30 ng) was applied to some of the non-chilled cuttings at three days intervals. Then, 12, 19, and 26 days after they were planted, the buds were sampled and processed for histological studies. Cultured flower buds (chilled or unchilled) had accelerated anther and gynoecium morphogenesis after 12 days under controlled conditions, compared to buds processed immediately after collection from the field. Chilling treatment augmented the bud culture effect, while Gibberellin A3 applications to the excised buds retarded bud morphogenesis to a stage comparable to that of buds collected directly from the field. This, suggests that the comparatively high levels of Gibberellin A1/3 we previously found in mid winter [15, 18] could be at least one of the factors that controls floral bud dormancy by retarding anther and gynoecium development. 相似文献
2.
J. T. Margaritopoulos C. Tsourapas M. Tzortzi O. M. Kanavaki J. A. Tsitsipis 《Ecological Entomology》2005,30(4):406-418
Abstract. 1. Myzus persicae sensu lato demonstrates considerable genetic variation in respect to adaptation to host plants. The subspecies M. persicae nicotianae shows a preference for tobacco, while M. persicae sensu stricto ( s. str. ) for other herbaceous plants. Given that winged colonisers of several aphid species play an important role in selecting host plants, here their role in the host specialisation observed in M. persicae was examined in choice and no-choice tests conducted outdoors, in performance studies, and in DC Electrical Penetration Graph (DC-EPG) studies.
2. In outdoor choice tests, 77% of spring migrants of M. persicae nicotianae chose tobacco, whereas equal proportions of M. persicae s. str. selected tobacco and pepper. In no-choice tests, spring migrants settled more quickly after alighting on host rather than on non host plants, and significantly more alate M. persicae s. str. (27%) than M. persicae nicotianae (2%) left tobacco after walking briefly on the leaf surface, whilst no significant differences were found on pepper. Cross-host transfers significantly reduced the fecundity of both summer and spring migrants of the two subspecies. Finally, the results of no-choice tests and DC-EPG studies showed that winged aphids distinguished their host through cues located on the plant surface or in subcutaneous tissues perceived prior to the initiation of feeding.
3. This study demonstrates the important role of winged colonisers in the evolution of host specialisation in M. persicae . The multifarious divergent selection that the two host forms experience, i.e. the selection against cross-migrants and their subsequent generations, is a crucial factor involved in the development and maintenance of host specialisation and promotes the parallel evolution of improved host-recognition ability. 相似文献
2. In outdoor choice tests, 77% of spring migrants of M. persicae nicotianae chose tobacco, whereas equal proportions of M. persicae s. str. selected tobacco and pepper. In no-choice tests, spring migrants settled more quickly after alighting on host rather than on non host plants, and significantly more alate M. persicae s. str. (27%) than M. persicae nicotianae (2%) left tobacco after walking briefly on the leaf surface, whilst no significant differences were found on pepper. Cross-host transfers significantly reduced the fecundity of both summer and spring migrants of the two subspecies. Finally, the results of no-choice tests and DC-EPG studies showed that winged aphids distinguished their host through cues located on the plant surface or in subcutaneous tissues perceived prior to the initiation of feeding.
3. This study demonstrates the important role of winged colonisers in the evolution of host specialisation in M. persicae . The multifarious divergent selection that the two host forms experience, i.e. the selection against cross-migrants and their subsequent generations, is a crucial factor involved in the development and maintenance of host specialisation and promotes the parallel evolution of improved host-recognition ability. 相似文献
3.
The shoot growth of compatible ( Prunus persica L. Batsch cv. Springtime grafted on Prunus cerasifera L. Ehrh cv. Myrobolan P2032) and incompatible ( Prunus persica L. Batsch cv. Springtime grafted on Prunus cerasifera L. Ehrh cv. Myrobolan P18) peach/plum grafts was observed over a period of 100 days after grafting under controlled conditions. Leaf and root activities were determined by studying carbon assimilation and partitioning, leaf mineral contents and water relations. Shoot length and leaf number were not significantly affected in the incompatible combination during the first 55 days after grafting, but then, shoot growth rate was significantly reduced. Final total dry weights of the shoot were similar in both graft combinations. The incompatible combination did not show any water stress. Soluble sugar and starch contents increased in the leaves of the incompatible combination, accounting for about 36% of the increase of leaf dry weight per unit area. Photosynthesis was affected by the compatibility of the grafts. Leaf nitrogen content (% dry weight) fell in the incompatible graft combination 65 days after grafting. However, nitrogen content on an area basis was not affected. The possibility of nitrogen stress is discussed. 相似文献
4.
Purification of an anionic isoperoxidase from peach seeds and its immunological comparison with other anionic isoperoxidases 总被引:3,自引:0,他引:3
A soluble anionic isoperoxidase (EC 1,11,1,7) was purified from peach ( Prunus persica L. Batsch cv. Merry) seeds. Purification was achieved by DEAE-Sephacel, Sephacryl S-300 and CM-cellulose chromatography. The purified isoperoxidase de-carboxylated indole-3-acetic acid (S0.5 0.13 m M , Hill coefficient 1.7). Molecular mass, determined by gel filtration and sodium dodecyl sulfate polyacrylamide gel electrophoresis, was ca 60 kDa. Polyclonal antibodies were raised in rabbit against this isoperoxidase. Using immunoprecipitation this isoenzyme was found to be immunologically different from other soluble anionic isoperoxidases isolated from peach seeds. 相似文献
5.
Two forms of exopolygalacturonase increase as peach fruits ripen 总被引:1,自引:0,他引:1
Abstract. Freestone peach cultivars are distinguished from clingstone cultivars by a more extensive softening of the mesocarp tissue, and by the separation of mesocarp and endocarp during ripening. Cultivars of both types have been reported to develop exopolygalacturonase activity during ripening, but the enzyme has not been characterized in any detail. During development of freestone peaches ( Prunus persica L. var Coronet), two exopolygalacturonase enzymes were detected 42, 65 and 85 d after full bloom and in ripe fruit. During ripening one enzyme (exoPG 1) increased 36-fold and the other (exoPG 2) 90-fold but exoPG 2 accounted for a 73% of the total activity in ripe fruit. ExoPG 1 was purified 24-fold and exoPG 2 540-fold. ExoPG 2 is a slightly acidic glycoprotein. ExoPG 1 and exoPG 2 differ slightly in their pH optima and in their responses to calcium: each produces monogalacturonic acid as a reaction product. Similar enzymes were found in Flavorerest, a semi-freestone peach. 相似文献
6.
R. C. H. Shepherd 《BioControl》1990,35(4):583-587
Host specificity tests carried out in the laboratory in Australia during 1977, showed thatMicrothrix inconspicuella Ragonot could develop on young apple leaves (Harley
et al., 1979). Field studies in unsprayed apple orchards in South Africa showed that some feeding occurred, but fewer than 40% of
late instar larvae developed to adults when confined in sleeves on apple tree branches. No feeding or survival occurred in
large field cages or in the open. Adults which developed from apple fed larvae were smaller, deformed, occasionally mated
and laid fertile eggs but their progeny did not feed or develop on apple fruit or leaves. In conclusion,M. inconspicuella larvae did not develop on apple fruit or leaves in the field, damage was mainly limited to apples already injured and feeding
on leaves was minimal. Under normal pest control practicesM. inconspicuella populations did not survive on any part of the apple tree or onE. australis growing under the trees.
相似文献
7.
Aerial dispersal of European red mite, Panonychus ulmi (Koch), in commercial apple orchards was estimated by trapping windborne mites. Studies were conducted at four orchards in eastern New York during 1989 and 1990 and at three orchards in western New York during 1989. In each orchard mites were trapped in three locations; the interior of the orchard, at the border of the orchard and in a field or woodlot beyond the orchard. Large numbers of mites were captured, even when the numbers of mites on apple foliage were well below levels where mite injury to leaves was visible (less than five per leaf). The log numbers of mites trapped were linearly related to the log density of mites on leaves and this relationship was consistent for each year and region the study was conducted. The trap captures among the three locations in and outside an orchard were highly correlated. The implications these findings may have on metapopulation dynamics and resistance to acaricide dynamics are discussed. 相似文献
8.
Isolation of cells and protoplasts from leaves of in vitro propagated peach (Prunus persica) plants 总被引:3,自引:0,他引:3
Yields of 106–108 peach mesophyll cells and protoplasts · gfw-1 were obtained depending on factors such as digesting enzymes, and leaf size. Onozuka R-10 (2%) in combination with Macerase (0.5%) was found best for protoplast isolation and mediocre for cell isolation among several enzyme combinations tested. Viability was 90% for protoplasts and 60% for cells. Pectolyase Y23 was found to be ineffective in our investigation. Small leaves, 4–10 mm in length, were a superior source for protoplast isolation than medium or big expanded leaves, 22–30 mm in length. The high yields of protoplasts could be obtained only when keeping the ratio of leaf biomass to volume of digesting enzyme solution under 20 mg ml-1. Purification of protoplasts on a sucrose gradient yielded about 107 protoplasts · gfw-1, however, the preparation was still contaminated by intact cells. Protoplasts were cultured under different growth regulators and physical conditions. Limited growth and division of protoplasts embedded in agarose drops were observed.Abbreviations BA
6-benzyladenine
- IBA
indolebutyric acid
- FDA
fluorescein diacetate
- MES
2-M-morpholinoethane sulphonic acid
- MS
Murashige and Skoog
- NAA
-naphthaleneacetic acid
- PVP
polyvinylpyrrolidone 相似文献
9.
10.
Alberto C. Q. Pinto David H. Byrne Suzanne M. Dethier Rogers 《In vitro cellular & developmental biology. Plant》1993,29(2):55-58
Summary Ovule perforation technique and media components (plant growth regulators andl-glutamine) were tested on in vitro growth of immature (<3 mm) embryos of “Springcrest” and “Earligrande” peaches. Ovule perforation
was 2 to 4 times more effective in promoting embryo growth than leaving ovules intact.l-Glutamine (400 mg·liter−1) promoted an increase in growth but could not be used with indole-acetic acid plus kinetin because an antagonistic effect
on embryo growth occurred. The use of these exogenous plant growth regulators did not increase embryo growth over in vivo
growth. 相似文献