Displaying publications 1 - 20 of 42 in total

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  1. Cockroach pollination and breeding system of Uvaria elmeri (Annonaceae) in a lowland mixed-dipterocarp forest in Sarawak
    Nagamitsu T, Inoue T
    Am J Bot, 1997 Feb;84(2):208.
    PMID: 21712200
    Tropical forest plants are known to be pollinated by a diverse array of animals. Here we report on the pollination of a woody climber species, Uvaria elmeri (Annonaceae), by cockroaches in a lowland mixed-dipterocarp forest in Sarawak, Malaysia. To the best of our knowledge, this is the first report of pollination by cockroaches. The cauliflorous flowers in the understory are protogynous and bloomed for 50 h. An odor similar to decayed wood or a mushroom was secreted by flowers and was stronger during the male stage. Pollinators were cockroaches (Blattellidae) and drosophilid flies (Drosophilidae). Cockroaches, the main pollinators, visited flowers during both female and male stages at night, feeding on stigmatic exudate and pollen. Drosophilids, the secondary pollinators. mainly visited female-stage flowers during daytime, fed on stigmatic exudate. and laid eggs on stigmas. Neither autogamy nor self-compatibility was observed. Fruit production appeared to be pollen-limited. The fruit set, which was 2% of flowers in natural condition, was significantly lower than the 30% fruit set obtained by artificial cross-pollination. We discuss the traits of cockroaches as pollinators and the breeding system of U. elmeri.
    Matched MeSH terms: Pollination
  2. Pollination biology in a lowland dipterocarp forest inSarawak, Malaysia. I. Characteristics of the plant-pollinator communityin a lowland dipterocarp forest
    Momose K, Yumoto T, Nagamitsu T, Kato M, Nagamasu H, Sakai S, et al.
    Am J Bot, 1998 Oct;85(10):1477-501.
    PMID: 21684899
    Flowerings and flower visitors were observed continuously in alowland dipterocarp forest in Sarawak, Malaysia, for 53 mo in1992-1996. Flower visitors of 270 plant species were observed orcollected, and pollinators were assessed by observing body contact tostigmas and anthers. We recognized 12 categories of pollination systems.Among them, plants pollinated by social bees included the largest numberof species (32%) and were followed by beetle-pollinated species(20%). Pollination systems were significantly related with somefloral characters (flowering time of day, reward, and floral shape), butnot with floral color. Based on the relationships between pollinatorsand floral characters, we described pollination syndromes found in alowland dipterocarp forest. The dominance of social bees and beetlesamong pollinators is discussed in relation to the general floweringobserved in dipterocarp forests of West Malesia. In spite of high plantspecies diversity and consequent low population densities of lowlanddipterocarp forests, long-distance-specific pollinators were uncommoncompared with theNeotropics.
    Matched MeSH terms: Pollination
  3. A new pollination system: dung-beetle pollination discovered in Orchidantha inouei (Lowiaceae, Zingiberales) in Sarawak, Malaysia
    Sakai S, Inoue T
    Am J Bot, 1999 Jan;86(1):56-61.
    PMID: 21680345
    Lowiaceae, a family of the Zingiberales, comprise 11 species in the single genus Orchidantha. Here we present the first report on the pollination of Lowiaceae and describe a new system of dung-beetle pollination from Sarawak, Borneo. Orchidantha inouei has a zygomorphic flower located just above the ground. Observations revealed that the plant is visited frequently and is pollinated by scarabaeid dung beetles, mainly members of the genus Onthophagus. All four species of Onthophagus collected on O. inouei have also been caught using traps baited with dung or carrion in Borneo. Onthophagus was presumably attracted to the dung-like odor of the flower. Pollination of O. inouei is different from other examples of beetle pollination in that its flower provides neither reward nor protected space. Dung beetles are excellent at following a particular dung scent. Orchidantha is the only genus that includes species lacking floral nectar. It is interesting that this deception pollination using dung beetles was found in Zingiberales, in which all known species have mutual and specialized relationships with their long-distance, but costly, pollinators-bees, birds, and bats.
    Matched MeSH terms: Pollination
  4. Beetle pollination of Shorea parvifolia (section Mutica, Dipterocarpaceae) in a general flowering period in Sarawak, Malaysia
    Sakai S, Momose K, Yumoto T, Kato M, Inoue T
    Am J Bot, 1999 Jan;86(1):62-9.
    PMID: 21680346
    Pollination ecology of an emergent tree species, Shorea (section Mutica) parvifolia (Dipterocarpaceae), was studied using the canopy observation system in a lowland dipterocarp forest in Sarawak, Malaysia, during a general flowering period in 1996. Although the species has been reported to be pollinated by thrips in Peninsular Malaysia, our observations of flower visitors and pollination experiments indicated that beetles (Chrysomelidae and Curculionidae, Coleoptera) contributed to pollination of S. parvifolia in Sarawak. Beetles accounted for 74% of the flower visitors collected by net-sweeping, and 30% of the beetles carried pollen, while thrips accounted for 16% of the visitors, and 12% of the thrips carried pollen. The apical parts of the petals and pollen served as a reward for the beetles. Thrips stayed inside the flower almost continuously after arrival, and movements among flowers were rare. Fruit set was significantly increased by introduction of beetles to bagged flowers, but not by introduction of thrips. Hand-pollination experiments and comparison of fruit set in untreated, bagged, and open flowers suggested that S. parvifolia was mainly outbreeding.
    Matched MeSH terms: Pollination
  5. Three pollination guilds and variation in floral characteristics of Bornean gingers (Zingiberaceae and Costaceae)
    Sakai S, Kato M, Inoue T
    Am J Bot, 1999 May;86(5):646-58.
    PMID: 10330067
    The pollinators of 29 ginger species representing 11 genera in relation to certain floral morphological characteristics in a mixed-dipterocarp forest in Borneo were investigated. Among the 29 species studied, eight were pollinated by spiderhunters (Nectariniidae), 11 by medium-sized Amegilla bees (Anthophoridae), and ten by small halictid bees. These pollination guilds found in gingers in Sarawak are comparable to the pollination guilds of neotropical Zingiberales, i.e., hummingbird-, and euglossine-bee-pollinated guilds. Canonical discriminant analysis revealed that there were significant correlations between floral morphology and pollination guilds and suggests the importance of plant-pollinator interactions in the evolution of floral morphology. Most species in the three guilds were separated on the plot by the first and second canonical variables. Spiderhunter-pollinated flowers had longer floral tubes, while Amegilla-pollinated flowers had wider lips than the others, which function as a platform for the pollinators. Pistils and stamens of halictid-pollinated flowers were smaller than the others. The fact that gingers with diverse morphologies in a forest with high species diversity were grouped into only three pollination guilds and that the pollinators themselves showed low species diversity suggests that many species of rare understory plants have evolved without segregating pollinators in each pollination guild.
    Matched MeSH terms: Pollination
  6. Plant reproductive phenology over four years including an episode of general flowering in a lowland dipterocarp forest,Sarawak, Malaysia
    Sakai S, Momose K, Yumoto T, Nagamitsu T, Nagamasu H, Hamid AA, et al.
    Am J Bot, 1999 Oct;86(10):1414-36.
    PMID: 10523283
    The first systematic observation of a general flowering, a phenomenon unique to lowland mixed-dipterocarp forests in Southeast Asia, is presented. During general flowering, which occurs at irregular intervals of 3-10 yr, nearly all dipterocarp species together with species of other families come heavily into flower. We monitored reproductive phenology of 576 individual plants representing 305 species in 56 families in Sarawak, Malaysia. Observations continued for 53 mo from August 1992 and covered one episode of a general flowering cycle. Among 527 effective reproductive events during 43 mo, 57% were concentrated in the general flowering period (GFP) of 10 mo in 1996. We classified 257 species into flowering types based on timing and frequency of flowering. The most abundant type was "general flowering" (35%), which flowered only during GFP. The others were "supra-annual" (19%), "annual" (13%), and "sub-annual" (5%) types. General flowering type and temporal aggregation in reproductive events were commonly found among species in various categories of taxonomic groups, life forms, pollination systems, and fruit types. Possible causes for general flowering, such as promotion of pollination brought about by interspecific synchronization and paucity of climatic cues suitable for flowering trigger, are proposed, in addition to the predator satiation hypothesis of Janzen (1974).
    Matched MeSH terms: Pollination
  7. Artocarpus (Moraceae)-gall midge pollination mutualism mediated by a male-flower parasitic fungus
    Sakai S, Kato M, Nagamasu H
    Am J Bot, 2000 Mar;87(3):440-5.
    PMID: 10719005
    A previously undescribed pollination system involving a monoecious tree species, Artocarpus integer (Moraceae), pollinator gall midges, and fungi is reported from a mixed dipterocarp forest in Sarawak, Borneo. The fungus Choanephora sp. (Choanephoraceae, Mucorales, Zygomycetes) infects male inflorescences of A. integer, and gall midges (Contarinia spp., Cecidomyiinae, Diptera) feed on the fungal mycelia and oviposit on the inflorescence. Their larvae also feed on the mycelia and pupate in the inflorescence. The gall midges are also attracted by female inflorescences lacking mycelia, probably due to a floral fragrance similar to that of male inflorescences. Because of the sticky pollen, dominance of Contarinia spp. in flower visitors, and pollen load observed on Contarinia spp. collected on both male and female inflorescences, Artocarpus integer is thought to be pollinated by the gall midges. Although several pathogenic fungi have been reported to have interactions with pollinators, this is the first report on a pollination mutualism in which a fungus plays an indispensable role. The pollination system described here suggests that we should be more aware of the roles fungi can play in pollinations.
    Matched MeSH terms: Pollination
  8. Bird-pollination of three Durio species (Bombacaceae) in a tropical rainforest in Sarawak, Malaysia
    Yumoto T
    Am J Bot, 2000 Aug;87(8):1181-8.
    PMID: 10948003
    Pollination ecology of three Durio species, D. grandiflorus, D. oblongus, and D. kutejensis (Bombacaceae), was studied in a lowland dipterocarp forest in Sarawak, Malaysia, during a peak flowering period when at least 305 species of plants bloomed in 1996. Durio has been reported to be pollinated by bats in Peninsular Malaysia. However, my observations of flower visitors and pollination experiments indicated that two species, D. grandiflorus and D. oblongus, were pollinated by spiderhunters (Nectariniidae) and that the other species, D. kutejensis, was pollinated by giant honey bees and bats as well as birds. Hand-pollination experiments showed that all three species were obligate outbreeders. A resource limitation in fruit production was suggested. The former two species were visited only by spiderhunters, and the bagged flowers that were opened for animal visitors only at night bore no fruit, while those that were opened only during the day bore fruits, at comparable fruiting ratios to open pollination. Durio kutejensis was observed to be visited by giant honey bees, birds, and bats at different times of day, and three series of bagged experiments that exposed the flowers to animal visitors at different times of day bore fruits at a comparable ratio to open-pollination.
    Matched MeSH terms: Pollination
  9. Fulltext Paternity analysis-based inference of pollen dispersal patterns, male fecundity variation, and influence of flowering tree density and general flowering magnitude in two dipterocarp species
    Tani N, Tsumura Y, Kado T, Taguchi Y, Lee SL, Muhammad N, et al.
    Ann Bot, 2009 Dec;104(7):1421-34.
    PMID: 19808773 DOI: 10.1093/aob/mcp252
    BACKGROUND AND AIMS: Knowledge of pollen dispersal patterns and variation of fecundity is essential to understanding plant evolutionary processes and to formulating strategies to conserve forest genetic resources. Nevertheless, the pollen dispersal pattern of dipterocarp, main canopy tree species in palaeo-tropical forest remains unclear, and flowering intensity variation in the field suggests heterogeneity of fecundity.

    METHODS: Pollen dispersal patterns and male fecundity variation of Shorea leprosula and Shorea parvifolia ssp. parvifolia on Peninsular Malaysian were investigated during two general flowering seasons (2001 and 2002), using a neighbourhood model modified by including terms accounting for variation in male fecundity among individual trees to express heterogeneity in flowering.

    KEY RESULTS: The pollen dispersal patterns of the two dipterocarp species were affected by differences in conspecific tree flowering density, and reductions in conspecific tree flowering density led to an increased selfing rate. Active pollen dispersal and a larger number of effective paternal parents were observed for both species in the season of greater magnitude of general flowering (2002).

    CONCLUSIONS: The magnitude of general flowering, male fecundity variation, and distance between pollen donors and mother trees should be taken into account when attempting to predict the effects of management practices on the self-fertilization and genetic structure of key tree species in tropical forest, and also the sustainability of possible management strategies, especially selective logging regimes.

    Matched MeSH terms: Pollination*
  10. Fulltext Studies on homalomeneae (araceae) of borneo v: a new species and new supergroup record, of homalomena from sabah, malaysian borneo
    Sulaiman B, Boyce PC
    Trop Life Sci Res, 2010 Dec;21(2):85-90.
    PMID: 24575201 MyJurnal
    Homalomena galbana Baharuddin S. & P.C. Boyce is described from the Maliau Basin Conservation Area, Sabah, representing the first species of the Homalomena Supergroup to be recorded from Sabah, and the first mesophytic species of the Supergroup to be described from Borneo. The species is illustrated and a brief discussion on the pollination role of interpistillar staminodes is presented.
    Matched MeSH terms: Pollination
  11. Physico-chemical and structural changes of red-fleshed dragon fruit (Hylocereus polyrhizus) during fruit development
    Jamaludin NA, Ding P, Hamid AA
    J Sci Food Agric, 2011 Jan 30;91(2):278-85.
    PMID: 21031359 DOI: 10.1002/jsfa.4182
    Determination of physico-chemical (weight, length, diameter, stomatal density, respiration rate, colour, soluble solids concentration, titratable acidity, chlorophyll and betacyanin content) and structural changes of red-fleshed dragon fruit (Hylocereus polyrhizus (Weber) Britton & Rose) was carried out from 5 to 35 days after pollination (DAP) in order to explain their growth, development, maturations and ripening stages.
    Matched MeSH terms: Pollination
  12. Fulltext Establishing the evidence base for maintaining biodiversity and ecosystem function in the oil palm landscapes of South East Asia
    Foster WA, Snaddon JL, Turner EC, Fayle TM, Cockerill TD, Ellwood MD, et al.
    Philos Trans R Soc Lond B Biol Sci, 2011 Nov 27;366(1582):3277-91.
    PMID: 22006968 DOI: 10.1098/rstb.2011.0041
    The conversion of natural forest to oil palm plantation is a major current threat to the conservation of biodiversity in South East Asia. Most animal taxa decrease in both species richness and abundance on conversion of forest to oil palm, and there is usually a severe loss of forest species. The extent of loss varies significantly across both different taxa and different microhabitats within the oil palm habitat. The principal driver of this loss in diversity is probably the biological and physical simplification of the habitat, but there is little direct evidence for this. The conservation of forest species requires the preservation of large reserves of intact forest, but we must not lose sight of the importance of conserving biodiversity and ecosystem processes within the oil palm habitat itself. We urgently need to carry out research that will establish whether maintaining diversity supports economically and ecologically important processes. There is some evidence that both landscape and local complexity can have positive impacts on biodiversity in the oil palm habitat. By intelligent manipulation of habitat complexity, it could be possible to enhance not only the number of species that can live in oil palm plantations but also their contribution to the healthy functioning of this exceptionally important and widespread landscape.
    Matched MeSH terms: Pollination
  13. Fulltext Impacts of logging on density-dependent predation of dipterocarp seeds in a South East Asian rainforest
    Bagchi R, Philipson CD, Slade EM, Hector A, Phillips S, Villanueva JF, et al.
    Philos Trans R Soc Lond B Biol Sci, 2011 Nov 27;366(1582):3246-55.
    PMID: 22006965 DOI: 10.1098/rstb.2011.0034
    Much of the forest remaining in South East Asia has been selectively logged. The processes promoting species coexistence may be the key to the recovery and maintenance of diversity in these forests. One such process is the Janzen-Connell mechanism, where specialized natural enemies such as seed predators maintain diversity by inhibiting regeneration near conspecifics. In Neotropical forests, anthropogenic disturbance can disrupt the Janzen-Connell mechanism, but similar data are unavailable for South East Asia. We investigated the effects of conspecific density (two spatial scales) and distance from fruiting trees on seed and seedling survival of the canopy tree Parashorea malaanonan in unlogged and logged forests in Sabah, Malaysia. The production of mature seeds was higher in unlogged forest, perhaps because high adult densities facilitate pollination or satiate pre-dispersal predators. In both forest types, post-dispersal survival was reduced by small-scale (1 m(2)) conspecific density, but not by proximity to the nearest fruiting tree. Large-scale conspecific density (seeds per fruiting tree) reduced predation, probably by satiating predators. Higher seed production in unlogged forest, in combination with slightly higher survival, meant that recruitment was almost entirely limited to unlogged forest. Thus, while logging might not affect the Janzen-Connell mechanism at this site, it may influence the recruitment of particular species.
    Matched MeSH terms: Pollination
  14. Genome characterization of a breeding line derived from a cross between Oryza sativa and Oryza rufipogon
    Keong BP, Harikrishna JA
    Biochem Genet, 2012 Feb;50(1-2):135-45.
    PMID: 22089543 DOI: 10.1007/s10528-011-9479-8
    A preliminary screening was conducted on BC3F1 and BC4F1 backcross families developed from crossing Oryza sativa (MR219) and O. rufipogon (IRGC105491). Despite earlier results showing that O. rufipogon alleles (wild introgression) contributed to both number of panicles (qPPL-2) and tillers (qTPL-2) at loci RM250, RM208, and RM48 in line A20 of the BC2F2 population, we observed that wild introgression was lost at loci RM250 and RM208 but retained at locus RM48 in BC3F1 and BC4F1. Progeny tests conducted utilizing genotype and phenotype data on both BC4F1 and a reference population, BC2F7 (A20 line), did not show significant differences between groups having the MR219 allele and wild introgression at locus RM48. This suggests that there is no additive and transgressive effect of wild introgression in the BC3F1 and BC4F1 generated. The presence of wild introgression was largely due to gene contamination by cross-pollination during field breeding practices.
    Matched MeSH terms: Pollination/genetics
  15. Fulltext Pollination mutualism between Alocasia macrorrhizos (Araceae) and two taxonomically undescribed Colocasiomyia species (Diptera: Drosophilidae) in Sabah, Borneo
    Takano KT, Repin R, Mohamed MB, Toda MJ
    Plant Biol (Stuttg), 2012 Jul;14(4):555-64.
    PMID: 22289145 DOI: 10.1111/j.1438-8677.2011.00541.x
    Two taxonomically undescribed Colocasiomyia species were discovered from inflorescences of Alocasia macrorrhizos in Kota Kinabalu City, Sabah, Borneo, Malaysia. The aims of this study were to investigate the reproductive ecology of the flies and the plant, ascertain the importance of the flies as pollinators and examine the intimate association between flowering events and life history of the flies. We conducted sampling, observations and field pollination experiments. The flies were attracted by the odour of female-phase inflorescences in the early morning on the first day of anthesis. They fed, mated and oviposited in the inflorescences for 1 day. On the second day, the flies, covered with pollen grains, left the male-phase inflorescences for the next female-phase inflorescences. The immature forms of both fly species hatched, developed and pupated within the infructescences without damaging the fruits, and developed adults emerged when the mature infructescences dehisced. The flowering events and fly behaviours were well synchronized. In field pollination experiments, inflorescences bagged with a fine mesh (insect exclusion) produced almost no fruits, whereas those bagged with a coarse mesh (bee exclusion) produced as many fruits as the open-pollinated controls. These results indicate that these flies are the most efficient and specialised pollinators for their host, A. macrorrhizos. These flies, in return, depend on A. macrorrhizos for food and habitat through most of their life cycle. This study provides a deeper insight into the less recognised, highly intimate pollination mutualism between Araceae plants and Colocasiomyia flies.
    Matched MeSH terms: Pollination*
  16. Importance of carpenter bee, xylocopa varipuncta (hymenoptera: apidae) as pollination agent for mangrove community of Setiu Wetlands, Terengganu, Malaysia
    Wahizatul Afzan Azmi, Roziah Ghazi, Nor Zalipah Mohamed
    Sains Malaysiana, 2012;41:1057-1062.
    A study on the importance of Xylocopa varipuncta (Hymenoptera: Apidae) as pollination agent was conducted at the Setiu Mangrove Forest, Terengganu from September to December 2010. The objective of this study was to identify the pollens collected by carpenter bees (X. varipuncta) in the mangrove community of Setiu Wetlands. A total of 35 types of pollens were collected from the body of X. varipuncta and only 10 types of the pollens were successfully identified. The identified pollens were of Avicennia alba, Lumnitzera racemosa, Sonneratia caseolaris, S. ovata and Rhizophora apiculata from exclusive mangroves, while Suregada multiflora, Melaleuca cajuputi, Derris trifoliata, Acacia auriculiformis and Hibiscus tiliaceus were from non-exclusive mangroves. Melaleuca cajuputi was the highest number of pollen carried by X. varipuncta. This study showed that X. varipuncta is an important pollen carrier in the mangrove community of Setiu Wetlands, Terengganu.
    Matched MeSH terms: Pollination
  17. Fulltext Non-density dependent pollen dispersal of Shorea maxwelliana (Dipterocarpaceae) revealed by a Bayesian mating model based on paternity analysis in two synchronized flowering seasons
    Masuda S, Tani N, Ueno S, Lee SL, Muhammad N, Kondo T, et al.
    PLoS One, 2013;8(12):e82039.
    PMID: 24391712 DOI: 10.1371/journal.pone.0082039
    Pollinator syndrome is one of the most important determinants regulating pollen dispersal in tropical tree species. It has been widely accepted that the reproduction of tropical forest species, especially dipterocarps that rely on insects with weak flight for their pollination, is positively density-dependent. However differences in pollinator syndrome should affect pollen dispersal patterns and, consequently, influence genetic diversity via the mating process. We examined the pollen dispersal pattern and mating system of Shorea maxwelliana, the flowers of which are larger than those of Shorea species belonging to section Mutica which are thought to be pollinated by thrips (weak flyers). A Bayesian mating model based on the paternity of seeds collected from mother trees during sporadic and mass flowering events revealed that the estimated pollen dispersal kernel and average pollen dispersal distance were similar for both flowering events. This evidence suggests that the putative pollinators - small beetles and weevils - effectively contribute to pollen dispersal and help to maintain a high outcrossing rate even during sporadic flowering events. However, the reduction in pollen donors during a sporadic event results in a reduction in effective pollen donors, which should lead to lower genetic diversity in the next generation derived from seeds produced during such an event. Although sporadic flowering has been considered less effective for outcrossing in Shorea species that depend on thrips for their pollination, effective pollen dispersal by the small beetles and weevils ensures outcrossing during periods of low flowering tree density, as occurs in a sporadic flowering event.
    Matched MeSH terms: Pollination/genetics; Pollination/physiology
  18. Morpho-molecular analysis as a prognostic model for repulsive feedback of the medicinal plant "Andrographis paniculata" to allogamy
    Valdiani A, Talei D, Javanmard A, Tan SG, Kadir MA, Maziah M
    Gene, 2014 Jun 1;542(2):156-67.
    PMID: 24680780 DOI: 10.1016/j.gene.2014.03.039
    Andrographis paniculata Nees. (AP) is a self-pollinated medicinal herb with a wide range of pharmaceutical properties, facing a low diversity in Malaysia. Cross-pollination of AP accessions leads to considerable rates of heterosis in the agro-morphological characteristics and anticancer phytochemicals of this eminent medicinal herb. However, the poor crossability of the plant at the interpopulation or intraspecific levels is an obstacle from the evolutionary and breeding points of view as an average of 4.56% crossability was recorded for AP in this study. Hence, this research aimed to elicit the impact of parental genetic distances (GDs) on the rate of crossability of AP using seven accessions in 21 possible cross combinations. To this end, a set of 55 randomly amplified polymorphic DNA (RAPD) primers and a total of 13 agro-morphological markers were employed to test the hypothesis. Twenty-two out of the 55 RAPD primers amplified a total of 257 bands of which 107 bands were found to be polymorphic. The principal component analysis (PCA) based on the RAPD markers revealed that the studied AP accessions were distributed to three distinct groups. Furthermore, it was noticed that even a minor increase in GD between two parents can cause a decline in their crossability. Unlike, the morphological-based GDs acted neutrally to crossability. This finding suggests that, despite the low genetic diversity among the Malaysian APs, a population prescreening using RAPD markers would be useful to enhance the rate of fruit set through selecting the genetically adjacent parents.
    Matched MeSH terms: Pollination
  19. Hormones, polyamines, and cell wall metabolism during oil palm fruit mesocarp development and ripening
    Teh HF, Neoh BK, Wong YC, Kwong QB, Ooi TE, Ng TL, et al.
    J Agric Food Chem, 2014 Aug 13;62(32):8143-52.
    PMID: 25032485 DOI: 10.1021/jf500975h
    Oil palm is one of the most productive oil-producing crops and can store up to 90% oil in its fruit mesocarp. Oil palm fruit is a sessile drupe consisting of a fleshy mesocarp from which palm oil is extracted. Biochemical changes in the mesocarp cell walls, polyamines, and hormones at different ripening stages of oil palm fruits were studied, and the relationship between the structural and the biochemical metabolism of oil palm fruits during ripening is discussed. Time-course analysis of the changes in expression of polyamines, hormones, and cell-wall-related genes and metabolites provided insights into the complex processes and interactions involved in fruit development. Overall, a strong reduction in auxin-responsive gene expression was observed from 18 to 22 weeks after pollination. High polyamine concentrations coincided with fruit enlargement during lipid accumulation and latter stages of maturation. The trend of abscisic acid (ABA) concentration was concordant with GA₄ but opposite to the GA₃ profile such that as ABA levels increase the resulting elevated ABA/GA₃ ratio clearly coincides with maturation. Polygalacturonase, expansin, and actin gene expressions were also observed to increase during fruit maturation. The identification of the master regulators of these coordinated processes may allow screening for oil palm variants with altered ripening profiles.
    Matched MeSH terms: Pollination
  20. Differential expression of the HvCslF6 gene late in grain development may explain quantitative differences in (1,3;1,4)-β-glucan concentration in barley
    Wong SC, Shirley NJ, Little A, Khoo KH, Schwerdt J, Fincher GB, et al.
    Molecular breeding : new strategies in plant improvement, 2015 01 20;35:20.
    PMID: 25620877
    The cellulose synthase-like gene HvCslF6, which is essential for (1,3;1,4)-β-glucan biosynthesis in barley, collocates with quantitative trait loci (QTL) for grain (1,3;1,4)-β-glucan concentration in several populations, including CDC Bold × TR251. Here, an alanine-to-threonine substitution (caused by the only non-synonymous difference between the CDC Bold and TR251 HvCslF6 alleles) was mapped to a position within HvCSLF6 that seems unlikely to affect enzyme stability or function. Consistent with this, transient expression of full-length HvCslF6 cDNAs from CDC Bold and TR251 in Nicotianabenthamiana led to accumulation of similar amounts of (1,3;1,4)-β-glucan accumulation. Monitoring of HvCslF6 transcripts throughout grain development revealed a significant difference late in grain development (more than 30 days after pollination), with TR251 [the parent with higher grain (1,3;1,4)-β-glucan] exhibiting higher transcript levels than CDC Bold. A similar difference was observed between Beka and Logan, the parents of another population in which a QTL had been mapped in the HvCslF6 region. Sequencing of a putative promoter region of HvCslF6 revealed numerous polymorphisms between CDC Bold and TR251, but none between Beka and Logan. While the results of this work indicate that naturally occurring quantitative differences in (1,3;1,4)-β-glucan accumulation may be due to cis-regulated differences in HvCslF6 expression, these could not be attributed to any specific DNA sequence polymorphism. Nevertheless, information on HvCslF6 sequence polymorphism was used to develop molecular markers that could be used in barley breeding to select for the desired [low or high (1,3;1,4)-β-glucan] allele of the QTL.
    Matched MeSH terms: Pollination
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