Fruit diet of Alouatta guariba and Brachyteles arachnoides in Southeastern Brazil: comparison of fruit type, color, and seed size

Fruit is an important food resource for neotropical primates. In this study I compare the fruit diet of sympatric brown howlers (Alouatta guariba) and southern muriquis (Brachyteles arachnoides). Feeding behavior was studied over 12 months and fruit species consumed were identified and assigned to the categories fruit type, fruit color, and seed size. Observed-fruit feeding records were compared with expected records determined from local availability of the fruit of the tree species. I also determined dietary overlap. Fruit consumption occupied 8 and 12% of the feeding time of A. guariba and B. arachnoides, respectively. Fruit from eight tree species were consumed by the former and fruit from twenty-two species by the latter. Patterns of fruit selection of A. guariba and B. arachnoides varied widely. Although howlers and muriquis converge behaviorally by selecting fruit with common attributes (fleshy/unprotected, violet and brown/black-colored), unlike A. guariba, B. arachnoides fed on immature seeds of fleshy/protected and dry fruit. Large seeds were ingested, and defecated intact, by B. arachnoides only. There was little overlap of fruit diet even within categories that had been selected by both, suggesting that dietary divergence is occurring at the interspecific level. Different resource exploitation probably mediates the coexistence of A. guariba and B. arachnoides in low diversity, semideciduous forests, where the environment imposes narrow limits on primate food choices.     

How fruit abundance affects the chimpanzee party size: a comparison between four study sites

We examined the relationship between fruit abundance and chimpanzee (Pan troglodytes) party size by comparing data from four study sites: the Kalinzu Forest Reserve, Uganda, the Djinji Camp and Guga Camp in the Ndoki Forest, Congo, and Kahuzi-Biega National Park, Democratic Republic of Congo. Although the difference in the fruit abundance between the sites was responsible for the difference in the party size between the sites, the seasonal changes in fruit abundance did not explain the changes in the party size in each study site. Across the four study sites, there were significant correlations of the mean and minimum of monthly party size with the mean of monthly fruiting-tree density, and a significant correlation of the maximum of monthly party sizes with the minimum of monthly fruiting-tree density. We proposed a hypothesis that (1) the monthly fruit abundance affects the monthly party size in the sites where the fruit availability is as low as to limit the party size during a major part of a year, while (2) the party size does not increase with the increase in the monthly fruit abundance, but is affected by other social factors, in the sites where the minimum of monthly fruit abundance is high enough for chimpanzees to form parties of an adequate size. Electronic Publication     

辣椒果色相关研究进展

辣椒是全球广泛种植的高经济价值茄科作物之一。在辣椒的各个经济性状中果色是最直观的重要性状之一。由于辣椒果色丰富多彩,目前已经成为研究果色遗传的一种模式植物。辣椒青熟果色与老熟果色存在差异且遗传、分子调控机制不同,本文将就辣椒这两个时期果色的遗传及分子调控机制研究做一个综述。     

Effect of controlled carbon dioxide on in vitro shoot multiplication in Feronia limonia (L.) Swingle

The effect of controlled carbon dioxide environment on in vitro shoot growth and multiplication in Feronia limonia (a tropical fruit plant, Family- Rutaceae) was studied. Carbon dioxide available in the ambient air of the growth room was insufficient for in vitro growth of the shoots alone. Also, the presence of sucrose only as the C-source in the medium (without CO₂), was found to be inadequate for sustainable growth and multiplication of shoots. The carbon dioxide enrichment promoted shoot multiplication and overall growth. The promotory effect of CO₂ was independent of the presence of sucrose in the medium. In the presence of both CO₂ and sucrose, an additive effect was observed producing maximum shoot growth. In the absence of sucrose a higher concentration of CO₂ (10.0)g m⁻³ was required to achieve photoautotrophic shoot multiplication comparable to ambient air controls. Highest leaf area per shoot cluster promoting shoot growth and multiplication was recorded under this treatment. Shoots growing on sucrose containing medium under controlled CO₂ environment of 0.6 g m⁻³ concentration evoked better response than ambient air controls (shoots growing on sucrose containing medium) in growth room. This treatment produced the overall best response. The present study highlighted the possibility of photoautotrophic multiplication which might prove useful for successful hardening and acclimatization in tissue culture plants.     

高氧对果蔬采后生理影响研究进展

高氧（21%-100%O2）贮藏是近几年发展起来的果蔬采后处理技术之一.概述了高氧对果蔬采后生理如呼吸作用、乙烯合成、组织褐变、活性氧代谢及抗氧化能力、风味等方面的影响,还介绍了高氧对病原微生物生长和采后果蔬腐烂控制的作用.     

Fruit color and fruit size of bird-disseminated plants in Japan

Fruit color, fruit size and phenology of bird-disseminated plants were examined in different climatic zones of Japan and the relationships between the plants and frugivorous birds were disscussed.Black fruit was the most common in warm-temperate areas and red was the most common in cool-temperate and subarctic zones. Red was more dominant in the lower layer of the forests in all climatic zones. Bicolor fruits were frequent in trees and were not found in herbs. Both in warm- and cool-temperate zones conspicuous fruits which are red and bicolored display were more frequent in summer than in winter.The diameter of most fruits were 4–11 mm. Fruits in warm-temperate were somewhat bigger than those in cooltemperate zone. In forest strata the fruits of shrubs were smaller than those of trees and herbs in width. However I found no relationships between fruit size and fruit color.The frugivorous birds could have influenced not only the evolution of seasonal differences in the proportion of fruit color between warm-temperate and cool-temperate region, but also affect the fruit size.     

The source of gibberellins in the parthenocarpic development of ovaries on topped pea plants

The role and source of gibberellins (GAs) involved in the development of parthenocarpic fruits of Pisum sativum L. has been investigated. Gibberellins applied to the leaf adjacent to an emasculated ovary induced parthenocarpic fruit development on intact plants. The application of gibberellic acid (GA₃) had to be done within 1 d of anthesis to be fully effective and the response was concentration-dependent. Gibberellin A₁ and GA₃ worked equally well and GA₂₀ was less efficient. [³H]Gibberellin A₁ applied to the leaf accumulated in the ovary and the accumulation was related to the growth response. These experiments show that GA applied to the leaf in high enough concentration is translocated to the ovary. Emasculated ovaries on decapitated pea plants develop without application of growth hormones. When [³H] GA₁ was applied to the leaf adjacent to the ovary a substantial amount of radioactivity accumulated in the growing shoot of intact plants. In decapitated plants, however, this radioactivity was mainly found in the ovary. There it caused growth proportional to the accumulation of CA₁. Application of LAB 150978, an inhibitor of GA biosynthesis, to decapitated plants inhibited parthenocarpic fruit development and this inhibition was counteracted by the application of GA₃ (either to the fruit, or the leaf adjacent to the ovary, or through the lower cut end of the stem). All evidence taken together supports the view that parthenocarpic pea fruit development on topped plants depends on the import of gibberellins or their precursors, probably from the vegetative aerial parts of the plant.Abbreviations FW flesh weight - GA_n gibberellin A_n - HPLC high-performance liquid chromatography     

Between-year variation in flowering and fruit set in frost-prone and frost-sheltered populations of dioecious Rubus chamaemorus

Summary The flowering and fruiting patterns of the dioecious perennial herb Rubus chamaemorus L. were studied in frost-prone (open) and frost-sheltered (Shaded) habitats in northern Sweden over 6 years. The number of ramets with flower buds, the proportion of flower buds that opened, and fruit set varied markedly between years. In the frost-prone populations, the occurrence or absence of detrimental frosts during the development of flowers and fruit could explain much of the variation, both in the proportion of flower buds that developed into flowers, and in fruit set. In the frost-sheltered populations, most female flowers that did not develop into fruit aborted without any signs of physical damage and before any ovules had begun to enlarge. Flower mortality caused by herbivores feeding on reproductive parts was commonly low, but reached values higher than 10% in one of the shaded populations. Hand-pollination increased the proportion of ovules producing seeds in the mature fruits by about 20%, and in one year also increased fruit set significantly in one population. Fruit-producing female ramets had a higher mortality and a lower probability of flowering in the subsequent year than male ramets and non-fruiting female ramets. In R. chamaemorus, the conditions for fruit maturation are highly unpredictable at the time of flower initiation. It is suggested that the apparent over-initiation of flower buds is advantageous, as it allows the plant to attain a high reproductive success in years favourable for flowering and fruit development.     

Plastid changes during the conversion of chloroplasts to chromoplasts in ripening tomatoes

Methods were developed for the isolation of plastids from mature green and ripening tomatoes (Lycopersicon esculentum Mill.) and purification by sucrose or Percoll density-gradient centrifugation. Assessment of the purity of preparations involved phase-contrast and electron microscopy, assays for marker enzymes and RNA extraction and analysis. Proteins were extracted from isolated plastids at different ripening stages and separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The profiles obtained from chloroplasts and chromoplasts showed many qualitative and quantitative differences. Labelling of proteins with [³⁵S]methionine in vivo showed that there was active protein synthesis throughout ripening, but there was a change in the plastid proteins made as ripening proceeded. The cellular location of synthesis of specific proteins has yet to be established.Abbreviations CS citrate synthase - EDTA ethylenediaminetetraacetic acid,-acetate - GAPDH NADP⁺-glyceraldehyde-3-phosphate dehydrogenase - rRNA ribosomal RNA - SDS sodium dodecyl sulphate - SDS-PAGE SDS-polyacrylamide gel electrophoresis - Tris 2-amino-2(hydroxymethyl)-1,3-propanediol     

Maturation characteristics of Rubus pennsylvanicus fruit: are black and red the same?

Summary Fruit of the blackberry, Rubus pennsylvanicus Poir. (Rosaceae), were examined to determine variation in maturation characteristics. Maturation timing and rate varied greatly among individual fruits, resulting in a bi-colored fruiting display comprised largely of two maturation stages, pre-ripe (salmon and scarlet) and ripe (dark brown and black). While ripe fruit were generally larger and heavier than pre-ripe fruit, exhibiting greater fresh and dry fruit weight, diameter, water content, and total seed weight, no significant differences were found in energy content, i.e. numbers of calories per gram pulp, or in pulp:seed ratio. The differences between ripe and pre-ripe fruit appear to be due largely to an increase in water content and seed weight with maturity. The fact that little energetic benefit accrues to the preferential selection of ripe fruit suggests that bi-colored Rubus displays may be considered to be unicolored.