The effect of partial flower removal on the relation betwen root, shootand fruti growth in the indeterminate tomato

The root, vegetative shoot and fruit growth of November and January sown glasshouse tomato plants grown in flowing water culture was followed over 6–7 months. The relationship between vegetative and reproductive growth was examined after two-thirds of the flowers were removed from half the experimental plants. This resulted in larger plants which had fewer, larger fruits and eventually a fruit yield almost as large as the controls. In the control plants, fruit growth increased steadily until it reached 90% of the total incremental fresh weight of the plant 50–60 days after first anthesis. Leaf growth was markedly depressed at this stage and root growth ceased 4 wk after anthesis. Some root death was observed from anthesis onwards. When fruit growth subsequently diminished, vegetative growth recovered but to a lower rate than before fruiting commenced. Following partial flower removal, only 64% or less of the total increment of fresh weight went into the fruit. Although vegetative growth at this stage was thus greater than in the control plants, both shoot and root growth followed the same qualitative pattern with time. The ratio of vegetative shoot to root fresh weight remained essentially constant throughout the fruiting phase in plants of both sowings whether flowers were removed or not. This suggests that the fruit grew in competition with the vegetative organs as a whole, although, for a short period at early fruiting, root growth was more seriously affected. The pattern and amount of fruiting in this indeterminate plant was influenced by the size of the vegetative organs at fruiting, and by the effect of the existing developing fruit on further vegetative and reproductive growth.     

Genetic correlations between vegetative growth traits and productivity at different within-season intervals for strawberries (Fragaria X ananassa)

Summary Genetic and environmental relationships between vegetative growth and production traits at different intervals within a single season were investigated using unselected strawberry genotypes from 20 biparental crosses and their parents. Vegetative growth and productivity patterns differed between test locations and larger yields were detected where fall growth was greatest. Positive genetic correlations were detected between fall growth increments and mid-season production traits, but fall growth was uncorrelated or negatively correlated with late-season production. Conversely, growth during the production season was genetically uncorrelated or negatively correlated to early production traits, but was positively correlated to mid and late-season production. Together, these results suggest that the growth pattern required for early vs sustained production may represent conflicting breeding objectives. Also, although vegetative and reproductive functions compete for assimilates in strawberry, sustained productivity appears dependent on adequate vegetative growth throughout the spring and early summer. Significant correlations were detected between fall plant growth and early yield, but these were attributed to environmental rather than genetic sources. Genetic correlations between spring growth and early production traits were significantly negative and large, suggesting that vegetative during this interval may indicate limited fall inflorescence development.     

To grow or to seed: ecotypic variation in reproductive allocation and cone production by young female Aleppo pine (Pinus halepensis, Pinaceae)

Age and size at the first reproduction and the reproductive allocation of plants are linked to different life history strategies. Aleppo pine only reproduces through seed, and, as such, early female reproduction confers high fitness in its infertile highly fire-prone habitats along the Mediterranean coast because life expectancy is short. We investigated the extent of ecotypic differentiation in female reproductive allocation and examined the relation between early female reproduction and vegetative growth. In a common-garden experiment, the threshold age and size at first female reproduction and female reproductive allocation at age seven differed significantly among Aleppo pine provenances of ecologically distinct origin. Significant correlations among reproductive features of the provenances and the ecological traits of origin were found using different analytical tools. In nonlinear models of cone counts vs. stem volume, medium-sized trees (not the largest trees) produced the highest cone yield, confirming that, at the individual level, early female reproduction is incompatible with fast vegetative growth. The contribution of founder effects and adaptation to contrasting fire regimes may be confounding factors. But considering all traits analyzed, the geographical patterns of resource allocation by Aleppo pine suggest ecotypic specialization for either resource-poor (favoring early reproduction) or resource-rich (favoring vegetative growth) habitats.     

Changes in volume,surface area,and frequency of nuclear pores on the vegetative nucleus of tobacco pollen in fresh,hydrated, and activated conditions

The vegetative nucleus (VN) of Nicotiana tabacum L. has been qualitatively and quantitatively studied in fresh, hydrated, and activated pollen. Techniques included the use of optical sectioning by confocal scanning laser microscopy to obtain volume and surface area measurements, and stereoscopic pairs; and freeze-etch electron microscopy to estimate the frequency of nuclear pores per m² in the vegetative nucleus. Several morphological changes were observed to occur in pollen grain nuclei during the early processes of tube growth. In freshly dehisced pollen grain, the vegetative and generative nuclei were side by side, but following hydration and activation of the grain, the elongated generative nucleus became partially surrounded by the vegetative nucleus. It was found that during hydration, the surface area of the vegetative nucleus increased and there was a decrease in the frequency of nuclear pores. The calculated total number of pores remained similar. After activation and pollen-tube growth, the vegetative nucleus retained the same surface area as in the hydrated state but the frequency of nuclear pores decreased; therefore, the calculated total number of pores was significantly lowered. When considered alongside complementary biochemical data, these morphological results indicate that RNA production in the vegetative nucleus decreases following germination.Abbreviations VN vegetative nucleus (nuclei) - GN generativenucleus - GC generative cell - CSLM confocal scanning laser microscope We acknowledge research support by the Biotechnology Action Programm of the Commission of European Communities, and CNR for the fellowship awarded to Dr. Wagner. We would also like to thank Mrs. C. Faleri for the expert technical help.     

Maximum Vegetative Growth Potential and Seasonal Patterns of Resource Dynamics during Peach Growth

The maximum vegetative growth potential of two peach [Prunuspersica (L.) Batsch] cultivars that differ in the timing ofresource demand for reproductive growth was determined in termsof stem extension, stem and leaf dry weight accumulation, andtrunk radial increment on defruited trees. The maximum vegetativegrowth potentials were similar on the two cultivars indicatingthat the greater partitioning of dry weight to vegetative growthfrequently observed on early maturing cultivars compared tolate maturing cultivars is the result of a shorter period ofcompetition between reproductive and vegetative growth, ratherthan a genetic difference in vegetative growth potential. Onboth cultivars, stem extension and leaf dry weight accumulationceased in mid-summer, however stem dry weight accumulation andtrunk radial increment increase continued through the autumn. The presence of fruit did not have a detectable effect on thefinal stem length, stem dry weight or leaf dry weight on theearly maturing cultivar, but it reduced final stem length anddry weight by 43 and 56%, respectively on the late maturingcultivar. The presence of fruit did decrease stem length, stemdry weight and leaf dry weight on the early maturing cultivarfor 1 month prior to and 1 month after fruit harvest. Fruitdecreased final trunk radial increment by 42 and 77% on theearly and late maturing cultivars, respectively. These reductionsin vegetative growth indicate that resource partitioning tovegetative growth was reduced by competition with fruit growth. Comparison of stem relative extension rates and stem and leafrelative growth rates on fruited and defruited trees indicatedthat vegetative growth was resource-limited shortly after vegetativebud break on fruited trees of both cultivars. This period ofresource-limited vegetative growth corresponded to a periodof resource-limited fruit growth identified in an earlier study.During the period of resource-limited vegetative growth, assimilatesupply was low due to low leaf area index, and carbohydratedemand was relatively high due to high vegetative and reproductivegrowth potentials, creating resource-limited growth conditions.Copyright1995, 1999 Academic Press Maximum vegetative growth potential, carbon economy, partitioning, resource availability, resource limitation, source-limited growth, growth analysis, relative growth rate, peach, Prunus persica (L.) Batsch     

Localization of the vegetative cell wall hydrolases LytC, LytE, and LytF on the Bacillus subtilis cell surface and stability of these enzymes to cell wall-bound or extracellular proteases

LytF, LytE, and LytC are vegetative cell wall hydrolases in Bacillus subtilis. Immunofluorescence microscopy showed that an epitope-tagged LytF fusion protein (LytF-3xFLAG) in the wild-type background strain was localized at cell separation sites and one of the cell poles of rod-shaped cells during vegetative growth. However, in a mutant lacking both the cell surface protease WprA and the extracellular protease Epr, the fusion protein was observed at both cell poles in addition to cell separation sites. This suggests that LytF is potentially localized at cell separation sites and both cell poles during vegetative growth and that WprA and Epr are involved in LytF degradation. The localization pattern of LytE-3xFLAG was very similar to that of LytF-3xFLAG during vegetative growth. However, especially in the early vegetative growth phase, there was a remarkable difference between the shape of cells expressing LytE-3xFLAG and the shape of cells expressing LytF-3xFLAG. In the case of LytF-3xFLAG, it seemed that the signals in normal rod-shaped cells were stronger than those in long-chain cells. In contrast, the reverse was found in the case of LytE-3xFLAG. This difference may reflect the dependence on different sigma factors for gene expression. The results support and extend the previous finding that LytF and LytE are cell-separating enzymes. On the other hand, we observed that cells producing LytC-3xFLAG are uniformly coated with the fusion protein after the middle of the exponential growth phase, which supports the suggestion that LytC is a major autolysin that is not associated with cell separation.     

Phenology and life cycle of the annual, <Emphasis Type="Italic">Chamaesyce maculata</Emphasis> (L.) Small (Euphorbiaceae), with multiple overlapping generations in Japan

The phenology of germination, vegetative growth and sexual reproduction in the annual Chamaesyce maculata (L.) Small (Euphorbiaceae) were investigated in a natural population in western Japan. Seedlings emerged from mid-June to early October, with three peaks: mid-June, late July and late August. Plants that emerged in June commenced sexual reproduction from late July, and thereafter both vegetative growth and sexual reproduction occurred together until early November, the plants showing no switching from vegetative growth to sexual reproduction. Seedlings that emerged in June and July suffered high mortality, but most seedlings that emerged from August onward survived until the reproductive stage. The minimum size for reproduction was largest for plants that emerged early in the season, and it decreased with a delay in seedling emergence. The late emergence of seedlings that resulted in low reproductive output may be to some extent compensated for by the increased probability of survival in the seedling stage. A transplant experiment clarified that C. maculata can repeat a maximum of three overlapping generations within a year. Multiple generations per year were attained by non-dormant seeds produced in the first and second generations and clearly resulted in an increased reproductive output per year. The life cycle with multiple overlapping generations may have been acquired in habitats where unpredictable disturbance results in temporally unsuitable conditions for germination, vegetative growth and sexual reproduction of annual plants, but where suitable conditions frequently continue over a period longer than the single generation time of annual plants.     

新疆郁金香营养生长、个体大小和开花次序对繁殖分配的影响

植物有性繁殖与资源分配的关系研究对于揭示植物生活史特征及繁育系统进化具有重要意义。新疆郁金香(Tulipa sinkiangensis)是新疆天山北坡荒漠带特有的一种多年生早春短命植物。在自然生境中,该物种仅以有性繁殖产生后代,每株能产生1-8朵花,且不同植株上的花数及果实数以及花序不同位置上的花与果实大小明显不同。本文通过对新疆郁金香有性繁殖与营养生长及植株大小的关系以及花序中不同位置花及果实间的资源分配研究,旨在揭示营养生长、个体大小及开花次序对其繁殖分配的影响。结果表明:在开花和果实成熟阶段,新疆郁金香植株分配给营养器官(鳞茎和地上营养器官)与繁殖器官的资源间均存在极显著的负相关关系(P<0.01),说明其植株的营养生长与生殖生长间存在权衡关系。多花是新疆郁金香的一个稳定性状,其植株上花数目、花生物量、果实生物量和种子数量与植株生物量间均呈极显著的正相关关系(P<0.01),说明新疆郁金香植株的繁殖分配存在大小依赖性。在具2-5朵花的新疆郁金香植株中,花序内各花的生物量、花粉数和胚珠数、结实率、果实生物量、结籽数、结籽率及种子百粒重按其开花顺序依次递减,说明花序内各花和果实的资源分配符合资源竞争假说。植株通过减少晚发育的花或果实获得的资源来保障早发育的花或果实获得较多的资源,从而达到繁殖成功。     

Differential expression of the chitin synthase genes of Aspergillus nidulans, chsA, chsB, and chsC, in response to developmental status and environmental factors

To understand the role of the chitin synthase genes of Aspergillus nidulans, we analyzed the expression of chsA, chsB, and chsC both by Northern blotting and by a vital reporter system with sgfp encoding a modified version of green fluorescent protein, sGFP. chsA was expressed specifically during asexual differentiation, but not during either vegetative growth or sexual differentiation. The expression of chsB was ubiquitous throughout the fungal body and relatively independent of the change in developmental status of the cells. chsC was expressed moderately during sexual development as well as during the early phase of vegetative growth, but was expressed weakly in old vegetative mycelia and in asexual structures. Furthermore its expression was spatially differentiated, i.e., relatively strong in young cleistothecia and in mature ascospores, but negligible in Hülle cells. Osmostress caused by high concentrations (up to 1.2M) of KCl or NaCl stimulated the expression of chsA and chsC, but not that of chsB. Sodium acetate, especially at high concentration (3%), strongly enhanced the expression of all the three genes. Neither heat shock nor the sugar carbon sources tested (glucose, sucrose, or lactose) affected the expression of any of the three chitin synthase genes.     

Optimal Reproductive Strategy of Plants, with Special Reference to the Modes of Reproductive Resource Allocation

Abstract A growth model for reproductive energy allocation pattern and schedule is proposed. Assumptions are as follows: (1) the assimilation rate for an individual is given by a logistic curve of vegetative dry weight; (2) size variability is expressed by the parameter W of the logistic curve (asymptotic value of vegetative dry weight); (3) a plant controls allocation of the assimilate to vegetative and reproductive structures so as to maximize the reproductive energy investment at the end of the growth period. The models were analyzed in comparison with field and experimental observations and gave reasonable explanations for the reproductive allocation pattern of individuals which reflects ecological preferences and life history characteristics, such as environmental conditions of habitats (stable or changing), length of life span (annual, biennial or perennial) and growth form (erectophile or planophile). Decreasing RA (reproductive allocation) with individual size and delayed switchover time from vegetative to reproductive growth were found in plants which occur in stable environments and have a more or less fixed growth period; in those which occur in changing environments where growth period depends on individual size, RAs that remain constant or increase with variations in individual size and early switchover time were detected. Most perennials conform to the former case, but annuals and biennials conform to the latter case. Under extremely overcrowded conditions, planophiles, which are much more subject to crowding effect than erectophiles, tend to have increasing RA with increasing size, while erectophiles tend to have almost constant RA irrespective of size. These trends are discussed in the light of the life history characteristics and ecological distribution of plant species studied.     

Endocellular fatty acid composition during batch growth and sporulation of Bacillus thuringiensis kurstaki

Bacillus thuringiensis kurstaki (HD-1) was grown on two different complex media to study its fatty acid composition during vegetative growth and sporulation. In contrast to literature results, iso-even branched-chain fatty acids were found to predominate after early vegetative growth and throughout sporulation.     

When, how and how much: Gender-specific resource-use strategies in the dioecious tree Juniperus thurifera

BACKGROUND AND AIMS: In dioecious species male and female plants experience different selective pressures and often incur different reproductive costs. An increase in reproductive investment habitually results in a reduction of the resources available to other demands, such as vegetative growth. Tree-ring growth is an integrative measure that tracks vegetative investment through the plant's entire life span. This allows the study of gender-specific vegetative allocation strategies in dioecious tree species thoughout their life stages. METHODS: Standard dendrochronological procedures were used to measure tree-ring width. Analyses of time-series were made by means of General Mixed Models with correction of autocorrelated values by the use of an autoregressive covariance structure of order one. Bootstrapped correlation functions were used to study the relationship between climate and tree-ring width. KEY RESULTS: Male and female trees invest a similar amount of resources to ring growth during the early life stages of Juniperus thurifera. However, after reaching sexual maturity, tree-ring growth is reduced for both sexes. Furthermore, females experience a significantly stronger reduction in growth than males, which indicates a lower vegetative allocation in females. In addition, growth was positively correlated with precipitation from the current winter and spring in male trees but only to current spring precipitation in females. CONCLUSIONS: Once sexual maturity is achieved, tree rings grow proportionally more in males than in females. Differences in tree-ring growth between the genders could be a strategy to respond to different reproductive demands. Therefore, and responding to the questions of when, how and how much asked in the title, it is shown that male trees invest more resources to growth than female trees only after reaching sexual maturity, and they use these resources in a different temporal way.     

Changes in glucosinolates during crop development in single- and double-low genotypes of winter oilseed rape (Brassica napus): II. Profiles and tissue-water concentrations in vegetative tissues and developing pods

The concentrations of glucosinolates in the tissue water of leaves, stems, floral buds and developing pods were measured at defined stages of development in four oilseed rape cultivars known to have different seed glucosinolate concentrations (Bienvenu, Ariana, Cobra and Capricorn). Five alkenyl, two aromatic and three indolyl compounds were identified in the vegetative and reproductive organs. Substantial differences developed in the profiles of compounds present during vegetative growth. The 2-hydroxy-3-butenyl glucosinolate was primarily associated with developing and mature seeds and germinated seedlings. The 4-pentyl glucosinolate occurred mainly during the later stages of vegetative growth in spring, when leaves contained higher concentrations than stems, and during the early stages of flowering. The 2-phenylethyl and 3-indolymethyl glucosinolates were present earlier in vegetative growth when similar concentrations were present in leaves and stems. Differences between cultivars in the tissue-water concentrations of individual glucosinolates were small during vegetative growth. The leaves of Cobra and Capricorn had smaller concentrations of the 3-pentyl glucosinolate than Bienvenu and Ariana especially early in spring, and the stems of Capricorn had smaller concentration of the 3-pentyl and 2-phenylethyl glucosinolates. Greater differences between cultivars developed during pod growth and involved large increases in the concentrations of the 2-hydroxy-3-butenyl and 3-butenyl glucosinolates, especially in Bienvenu and Ariana. The implications of these changes in the types and concentrations of glucosinolates in the different organs for the incidence of pests and diseases are discussed.     

Studies of Growth and Flowering in Picea sitchensis (Bong.) Carr. 2. Initiation and Development of Male, Female and Vegetative Buds

Vegetative shoots from the base of the crown, and from partsof the tree likely to form male or female buds, were collectedfrom 40–years–old trees of Picea sitchensis (Bong.)Carr. throughout the 1973–4 annual growth cycle. The morphologyand growth rates of the terminal buds on these shoots were assessed. Bud scale primordia were formed most quickly in the female position,at an intermediate rate in the male position and most slowlyin the basal vegetative position during April, May and June.In July and early August the apical meristems swelled to formdomes and continued to grow at the same relative rates in themale, female and basal vegetative positions. Reproductive budswere first morphologically distinct in late August and sporangiaappeared in October. Dormancy, defined by the pause in apicalvolume increase, extended from mid-October to mid–March.Young strobili grew much faster than basal vegetative shootsof the same age between mid–March and bud burst in lateApril. Throughout the growth cycle, external changes in budsize reflected changes in size of the apical meristem, youngstrobihis or young vegetative shoot inside the bud. It is proposed that the rate of growth of an apical meristemmay be causally related to the type of bud which subsequentlydevelops from it. Sitka spruce, Picea sitchensis, bud development, morphology, growth of apical dome, flowering     

How do sink and source activities influence the reproduction and vegetative growth of spring ephemeral herbs under different light conditions?

Spring ephemeral herbs inhabiting deciduous forests commonly complete reproduction and vegetative growth before canopy closure in early summer. Effects of shading by early canopy closure on reproductive output and vegetative growth, however, may vary depending on the seasonal allocation patterns of photosynthetic products between current reproduction and storage for future growth in each species. To clarify the effects of sink–source balance on seed production and bulb growth in a spring ephemeral herb, Gagea lutea, we performed a bract removal treatment (source reduction) and a floral-bud removal treatment (sink reduction) under canopy and open conditions. Leaf carbon fixations did not differ between the forest and open sites and among treatments. Bract carbon fixations were also similar between sites but tended to decrease when floral buds were removed. Seed production was higher under open condition but decreased by the bract-removal treatment under both light conditions. In contrast, bulb growth was independent of light conditions and the bract-removal treatment but increased greatly by the bud-removal treatment. Therefore, leaves and bracts acted as specialized source organs for vegetative and reproductive functions, respectively, but photosynthetic products by bracts were flexibly used for bulb growth when plants failed to set fruits. Extension of bright period was advantageous for seed production (i.e., source limited) but not for vegetative growth (i.e., sink limited) in this species.     

Hormonal Profile in Vegetative and Floral Buds of Azalea: Levels of Polyamines, Gibberellins, and Cytokinins

The floral transition includes a complex system of factors that interact and involve various biochemical signals, including plant growth regulators. The physiological signals involved in the control of the floral transition have been sparsely studied and mainly in plant species whose genetics are poorly known. In this work, the role of polyamines, gibberellins, and cytokinins was investigated by analyzing their endogenous content in vegetative and floral buds of azalea. The results showed that there is a clear distinction between floral and vegetative buds with respect to the levels of these plant hormones, with floral buds containing higher amounts of conjugated polyamines, gibberellins (GAs) from the non-13-hydroxylation pathway (GA₉, GA₇, and GA₄), and cytokinins (particularly isopentenyl-type species), and vegetative buds containing higher amounts of free polyamines and gibberellins from the early 13-hydroxylation pathway and fewer cytokinins. In conclusion, there is a specific pattern of endogenous hormone profiles in both vegetative and floral bud development in azalea, which may be relevant for future research on the control of flowering by exogenous hormone applications.     

Influence des corrélations entre organes sur la croissance et le développement floral des bourgeons cotylédonaires chez leScrofularia arguta Sol.

The importance of various correlative influences on growth and vegetative or floral development of cotyledonary buds inScrofularia arguta Sol. is shown. The terminal bud, on the one hand, inhibits growth of cotyledonary buds and, on the other hand, induces their early flowering. The cotyledon stimulates growth of its axillary bud, but has no action on its floral development. Leaves above the cotyledonary node have the same effect as the cotyledon. Finally, roots stimulate vegetative growth of cotyledonary buds and suppress floral expression, but only when apical dominance has been removed at an early stage of development.     

Vegetative, reproductive, and physiological Adaptations to aridity of pitayo (Stenocereus queretaroensis, Cactaceae)

Pitayos fStenocereus spp.) are columnar cacti that produce attractive edible fruits under both wild and cultivated conditions. Until recently the study of pitayos has been relatively neglected even though they have been a crucial staple for the inhabitants of subtropical semiarid lands of Mexico since ancient times and this century have become an important fruit crop there. The main objective of this review is to relate seasonal aspects of vegetative and reproductive growth, CO₂ uptake, and carbohydrate resources to abiotic components of the environment. Flower and fruit production occur during the dry season in the late winter and spring, roots grow during the summer wet season, and stem elongation commences in the autumn at the beginning of the dry season. Vegetative growth thus does not coincide with reproductive growth, as it does for other fruit crops in temperate and tropical regions. The time offset of vegetative and reproductive activities reduces competitive sink effects, regulating assimilate partitioning to different organs, which may allow Stenocereus queretaroensis to adapt to water-limited environments. Reserve carbohydrates (starch, mucilage) accumulate in the early summer just after reproductive growth and in the early winter just after stem extension. Reducing sugars increase during the middle of the summer before stem elongation begins. The low rates of growth and of photosynthesis for S. queretaroensis are associated with low tissue levels of nitrogen, chlorophyll, and some micronutrients (Fe, Mn). Low levels of gibberellic acid may also contribute to its low growth rate. It does not respond morphologically to irrigation during the dry period, indicating a low plasticity for growth. Although S. queretaroensis is cultivated, its physiological and phenological activities closely resemble those of wild CAM species and other wild perennial plants, reflecting its rather recent domestication and the fact that selections were based mainly on fruit quality and adaptation to aridity rather than biomass productivity.     

Cross-species global proteomics reveals conserved and unique processes in Phytophthora sojae and Phytophthora ramorum

Phytophthora ramorum and Phytophthora sojae are destructive plant pathogens. P. sojae has a narrow host range, whereas P. ramorum has a wide host range. A global proteomics comparison of the vegetative (mycelium) and infective (germinating cyst) life stages of P. sojae and P. ramorum was conducted to identify candidate proteins involved in host range, early infection, and vegetative growth. Sixty-two candidates for early infection, 26 candidates for vegetative growth, and numerous proteins that may be involved in defining host specificity were identified. In addition, common life stage proteomic trends between the organisms were observed. In mycelia, proteins involved in transport and metabolism of amino acids, carbohydrates, and other small molecules were up-regulated. In the germinating cysts, up-regulated proteins associated with lipid transport and metabolism, cytoskeleton, and protein synthesis were observed. It appears that the germinating cyst catabolizes lipid reserves through the beta-oxidation pathway to drive the extensive protein synthesis necessary to produce the germ tube and initiate infection. Once inside the host, the pathogen switches to vegetative growth in which energy is derived from glycolysis and utilized for synthesis of amino acids and other molecules that assist survival in the plant tissue.