996 resultados para Zizania latifolia


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稻族(Oryzeae)是禾本科中包含多种经济植物的重要类群,现有大约12个属,广布于全球的热带和温带地区。虽然有证据表明稻族是一个单系类群,但稻族的分类处理和属间系统发育关系以及稻族的生物地理学等方面仍存在许多悬而未决的问题。本研究利用了7个DNA片段,包括2个叶绿体基因片段(trnL和matK)、1个线粒体基因片段(nad1)和4个分布在不同染色体上的核基因片段(Adh1、Adh2、GPA1和Waxy)以及形态性状(87个)重建了稻族的系统发育关系,并在此基础上利用6个DNA片段(trnL、matK、nad1、Adh1、Adh2和GPA1)探讨了稻属基部类群的系统发育关系。同时在系统发育研究的基础上,进一步探讨了稻族物种间的分歧时间及生物地理学问题。主要结果如下: 1.稻族的系统学 多基因和形态性状的分析表明:1)稻族是单系类群可分为两个主要分支,相当于传统的两个亚族,第一个亚族(Zizaniinae)包括稻属﹑假稻属和Porteresia,而第二个亚族(Oryzinae)包括其余8个属。两性花是稻族的原始状态,而单性花多次起源,共起源了3次,因此单性花和两性花的区别不宜作为划分亚族的依据;2)Zizania 与分布在南美的单型属Rhynchoryza关系最近;3)一些单型属(Hydrochloa、Porteresia和Prosphytochloa)的确立得不到分子证据的支持,特别是Hydrochloa,形态证据分析的结果明确不支持建立该单型属;4)形态分析结果支持Zizania 4个种聚为一支,而东亚的一个种(Zizania latifolia)为该属基部类群。 2.稻属基部类群的系统发育关系 多基因系统发育分析表明:1)稻属是一个单系类群;2)所有数据都支持稻属10种染色体组类型各自为单系,包括稻属中最后确定的染色体组类型HK(Oryza schlechteri和Porteresia coarctata);3)F染色体组与HK和HJ中的H染色体组关系最近,类似于E染色体组与异源四倍体的CD染色体组中的D染色体组关系最近; 4)双亲遗传的核基因和母系遗传的线粒体和叶绿体基因的对比分析表明,HJ染色体组两个物种的母系来源是H,而HK染色体组两个物种母系来源是K。三个染色体组相比较,H分化较早,J次之,K分化最晚;5)在系统发育研究基础上,本研究认为稻属4个复合体的划分是可信的,原来未划分到任何一个复合体中的两个种O. brachyantha和O. schlechteri以及新近归入稻属的Oryza coarctata都应归入O. ridleyi复合体。 3.稻族各谱系的分化时间及其生物地理学意义 利用分子钟及其改进方法对稻族各谱系的起源和分化时间进行了估测,并在此基础上探讨了形成各类群地理分布式样的可能原因。结果表明,稻族在始新世(Eocene)晚期(3640万年前)起源于东南亚随后分为两大支。稻属基部类群G染色体组物种与稻属其他物种在1200万年前分开;稻属中A/B/C/E染色体组类群在700万年前开始分化。 在稻族的第一大支Oryzinae亚族中,稻属和假稻属1400万年前分开后,通过远程扩散及随后的漫长的历史过程形成了目前的分布格局。稻属从东南亚起源并逐渐扩散到非洲、澳洲及美洲;而假稻属则从非洲出发扩散到全球的热带和亚热带地区。这两个属的演化历史非常相似,都是全球广泛分布且起源时间较晚。 在稻族第二大支Zizaniinae亚族中,Zizania是稻族中唯一欧亚-北美间断分布属,与其分布在南美的姊妹群Rhynchoryza在2554万年前分开,这一支可能是先从南美扩散到东亚,然后再从东亚扩散到北美;Zizaniopsis和Luziola两属在南美洲和北美洲都有分布,其分歧时间为2180万年前,这两属具有类似的进化历史,即通过上新世(Pliocene)末期隆起的巴拿马陆桥形成现在的分布格局;Chikusichola与Potamophila/Prosphytochloa这一支从中新世(Miocene)早期(2270万年前)开始分化,由于Chikusichola(分布在东南亚)、Potamophila(澳大利亚)和Prosphytochloa(非洲)相距很远,这3个属的扩散必然与跨洋远距离扩散有关。

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近几十年来,栽培作物及其野生近缘(祖先)种的群体遗传结构和进化历史的研究日益受到关注,因为此类研究不仅能加深人们对作物起源和驯化的认识,而且有助于作物野生资源的开发以及作物的遗传改良。分子谱系地理分析(Molecular phylogeography)是此类研究中的重要手段之一,能够有效地了解近缘群体的进化历程以及重建作物的驯化历史。菰(Zizania latifolia Turcz.)是东亚广泛分布、具有重要价值的水生草本植物,其栽培型—茭白是中国第二大水生蔬菜。尽管已有不少涉及此类群的研究,但迄今我们对菰的群体遗传结构和进化历史以及茭白的起源几乎一无所知。本研究从29个基因片段中筛选了2个在菰种内水平上具有显著变异量的核基因片段,进行了分子谱系地理研究,揭示了菰的遗传多样性水平及其地理分布格局,探讨了菰的群体演化历史,并初步探讨了茭白的起源和驯化历史。主要结果如下: 1)基因片段筛选 开展分子谱系地理学研究,需要采用具有显著种内变异的分子标记,为此我们通过预实验对一批备选基因片段进行了筛选。在18个叶绿体和2个线粒体片段中,测序的总长度达17100 bp,但没有发现任何变异位点。在9个核基因片段中,7个片段具有变异位点,但只有2个片段的变异量在1%以上,分别是Adh1a(2.70%)和GPATb(1.25%)基因。所以,本研究最后确定了采用这2个核基因片段来进行菰的分子谱系地理的研究。 2)Adh1a基因谱系地理分析 对来自21个天然群体126个个体,通过Adh1a基因的直接PCR和克隆测序共得到了252条序列,中性检测表明,Adh1a基因符合中性进化模型、没有重组并且有足够的变异量,适合用于进行菰的谱系地理研究和进化历史的推断。在物种水平上,菰的核苷酸多态性水平为θsil = 0.0089,跟一些作物近缘类群相比处于中等偏低的水平;不同群体的核苷酸多态性水平相差明显,多态性最高的群体出现在东北地区,并有从北向南递减的趋势。群体间存在着显著的遗传分化(FST = 0.481)表明群体之间的基因流有限。群体间的遗传距离与地理距离没有相关性,地理邻近的群体并没有共享关系相近的单倍型,整个群体缺乏明显的谱系地理结构。目前的遗传多样性分布格局可能是由于近几十年来的生境退化和丧失造成过去群体的片段化所致。根据群体遗传多样性水平的差异和基因谱系的地理分布格局以及分子钟估算的与北美近缘种的分化时间,我们推断菰的群体经历了从东北向华南逐步扩散的过程。 3)GPATb基因谱系地理分析 为更可靠地推断菰的谱系地理格局,我们选择了GPATb基因作为标记开展了进一步的分析。对相同的采样群体和个体共252条序列的分析表明,在物种水平上,GPATb的核苷酸多态性只相当于Adh1a基因的1/4。综合2个基因的结果,可以认为菰的核苷酸多态性水平是维持在较低的水平上。该位点体现的群体遗传分化也没有Adh1a基因明显。群体之间相近的遗传多样性水平和较低分化程度可能意味着该基因位点受到平衡选择作用的影响,这一推论也得到了中性检测结果的支持。因此,GPATb基因可能受到选择作用的影响,不能用来支持或推翻Adh1a基因的结果。 4)茭白的起源和驯化 对来自13个省份的65个茭白品种的Adh1a和GPATb基因片段进行测序,结果发现,所有的品种在这2个基因上都具有相同的基因型,Adh1a位点上表现为杂合体,而GPATb位点上则是纯合体。这说明在茭白的起源过程中发生了严重的驯化瓶颈效应,也即茭白是单次起源的,是从菰的少数几个甚至单个个体驯化而来。虽然文献考据表明,茭白最早的栽培地区为太湖流域,但我们的分子证据却并不支持其为茭白的驯化起源地点,而可能是在太湖流域以北地区起源的。鉴于采样的局限性,这一结论还有待于进一步的验证。同时2个基因的数据表明来自陕西、四川、云南、湖南和福建的6个菰群体可能是从人为引种的茭白逃逸成为野生的。因此,在以后野生菰群体的采集中,特别是在茭白种植地区,要在详细调查的基础上设计采集方案。

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<正> 茭草又称野菰(Zizania latifolia),广泛分布于我国内陆水体,在湖北省洪湖中,茭草是沿岸呈环带状分布的优势挺水植物。由于该湖年平均水深仅1.35米,底泥肥沃,适于茭草生长繁殖,群落面积已达22.7万亩,占该湖总面积的42%。每年生产茎叶干物质达15万吨以上,但绝大部分废弃分解还湖,未被充分利用。根据洪湖大水面水体生物生产力综合开发利用研究计划,我们对茭草不同器官化学成分分析的结果证明,茭草乃优质饲料,茭草叶含粗蛋白16.8—18.7%,其必需氨基酸组成比例与草鱼肌

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野菰(Zizania latifolia)是湖北省洪湖中优势水生维管束植物,其群落占全湖355平方公里面积的127平方公里。茎和叶的年生物量为4379克鲜重/平方米,全湖总年产量121700吨干重,目前未被利用。野菰各器官的蛋白质和氨基酸含量分别以百分干重表示:根,7.0和4.76;根状茎,11.3和8.85;茎,9.5和7.15;嫩茎梢,22.4和16.53;叶,16.8和14.61。500克干叶的必需氨基酸含量接近100克干重草鱼幼鱼背肌的必需氨基酸含量。脂肪:叶中3.4~4.2,茎中2.2;粗纤维:

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Induction of single and multiple shoots was obtained from nodal expiants of 60–80 year-old elite trees of rosewood on Murashige and Skoog's basal medium supplemented with 6-benzylaminopurine (1.0 mg 1-1) and delta -Naphthalene acetic acid (0.05 mg 1-1) or indole acetic acid (0.5 mg 1-1). Multiplication of shoots was obtained on MS (reduced major elements) or Woody Plant Medium supplemented with 6-benzylaminopurine (1.0 mg 1-1) and kinetin (0.5–1.0 mg 1-1). Excised shoots were rooted on half-strength MS with IBA (2.0 mg 1-1) to obtain complete plantlets. The regenerated plantlets have been acclimatized and successfully transferred to the soil.

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Direct regeneration of somatic embryos was obtained from immature zygotic embryos of Dalbergia latifolia. Immature embryos dissected from green pods 90 d after flowering gave the highest frequency of somatic embryo formation. Preculture on high 2,4-D medium for 4 weeks induced direct somatic embryogenesis, which was expressed during the second culture phase in the presence of low 2,4-D along with a high sucrose concentration. Embryos were separated and transferred to the maturation medium containing MS + 0.5-1.0 mg/L BAP, where embryos developed into plantlets. Somatic embryos failed to convert into complete plants without BAP treatment. This method of direct regeneration of somatic embryos without a callus phase has direct application for genetic manipulation studies.

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The sympatrically occurring Indian short-nosed fruit bat Cynopterus sphinx and Indian flying fox Pteropus giganteus visit Madhuca latifolia (Sapotaceae), which offers fleshy corollas (approximate to 300 mg) to pollinating bats. The flowers are white, tiny and in dense fascicles The foraging activities of the two bat species were segregated in space and time. Cynopterus sphinx fed on resources at lower heights in the trees than P giganteus and its peak foraging activity occurred at 19 30 h, before that of P giganteus Foraging activities involved short searching flights followed by landing and removal of the corolla by mouth Cynopterus sphinx detached single corollas from fascicles and carried them to nearby feeding roosts, where it sucked the juice and spat out the Fibrous remains Pteropus giganteus landed on top of the trees and fed on the corollas in situ, its peak activity occurred at 20 30 11 This species glided and crawled between the branches and held the branches with claws and forearms when removing fleshy corollas with Its Mouth Both C sphinx and P giganteus consumed fleshy corollas with attached stamens and left the gynoecium intact Bagging experiments showed that fruit-set in bat-visited flowers was significantly higher (P < 0.001) than in self-pollinated flowers.

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人工湿地污水处理系统具有净化效果显著、建设和运行费用低廉、管理简便等优点.近年来越来越受到人们的重视.人工湿地生态系统受环境影响较大,研究人工湿地在不同季节的净化功能对于充分发挥其作用具有重要意义.对不同季节的芦苇(Phragmite saus-tralis)、茭白(Zizania caduciflora)和香蒲(Typha latifolia)等湿地系统植物根区、无植物对照基质微生物分布状况以及净化效果进行了研究,结果显示:(1)种植不同植物的湿地系统根区微生物数量不同,其湿地净化效果也不同;(2)季节

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Summary Several studies have demonstrated that the number of pollen donors siring seeds of individual fruits is frequently greater than one and, consequently, that plants have multiple mates. Multiple paternity can have important consequences at the population level. It influences the genetic variability of a population, the reproductive success of males and the fitness of females and future generations. It also influences male-male interactions for fertilization and it is fundamental in providing opportunity of female choice. I investigated the occurrence and the importance of multiple paternity within fruits in natural populations of the dioecious Silene latifolia using microsatellite DNA markers, especially developed for this study. I found that multiple paternity occurs in all populations investigated in the European range of the species, varying from one to nine sires per fruit with a mean of three, suggesting that multiple paternity is highly prevalent in natural populations. In the presence of multiple paternity I investigated if there was a female genotype influence on siring success of the males. I used the same pollen mixture from two males and applied it to three replicate females of different relatedness (two full sisters and one unrelated). I found female genotype influence in one of the two populations investigated, which might reflect different population history. Since these results suggested some degree of female choice, we investigated whether the occurrence of multiple paternity and post-pollination selection could provide opportunity for inbreeding avoidance. First, I measured inbreeding depression at different life-cycle stages for offspring obtained by single-donor crosses with brothers or unrelated males replicated on distinct flowers on the same female plant. To address inbreeding avoidance, I determined paternity in crosses using mixed pollen loads of the two males. I found significant inbreeding depression in the studied population, even under benign experimental conditions, and although the unrelated male did not sire significantly more offspring, there was an effect of genetic dissimilarity on paternity. This suggests that paternity is affected by relatedness among mates, but maybe additionally affected by other factors such as pollen competitive ability or male-female interactions. Using inbred and outbred crosses, I further investigated sex ratio bias inheritance in this species, and found that sex ratio bias of the parental generation was significantly correlated to pollen germination success of the F2 generation, which suggests that sex ratio bias in this species results from the specific X/Y combination and not only on Y performance. An effect of X and Y is consistent with sex chromosome meiotic drive. In conclusion, I found multiple paternity to be widespread in the study species and that females of similar genotype produce similar paternity shares. I found that inbreeding depression is substantial, therefore receiving pollen from several donors might lead to fewer inbred offspring, I also found an effect of genetic dissimilarity on paternity shares, which indicates that there is some ability to discriminate against related pollen, although this seems not to be the only determinant of paternity outcome. Finally I found sex ratio bias to be dependent on both X and Y chromosomes as predicted by sex chromosome meiotic drive. Résumé Plusieurs études ont démontré qu'il n'était pas rare que les graines contenues dans un même fruit soient issues de la fécondation par plusieurs pollens provenant de mâles différents, ce qui sous-entend que les plantes peuvent avoir plusieurs partenaires sexuels. La paternité multiple peut avoir d'importantes conséquences au niveau populationnel dans la mesure où elle peut influencer le degré de variabilité génétique de la population, le succès reproducteur des mâles, la fitness des femelles et des futures générations. La paternité multiple peut également avoir un impact sur les interactions mâle-mâle lors de la fertilisation et peut être considérée comme fondamentale vis-à-vis de la femelle, qui y trouve alors une opportunité de choisir son ou ses partenaires. Dans le cadre de ce travail de thèse j'ai cherché à déterminer si la paternité multiple était un phénomène observable et important dans les populations naturelles de l'espèce dioïque, Silene latifolia. Pour ce faire, j'ai utilisé des marqueurs microsatellites, spécialement développés pour cette étude. J'ai observé des phénomènes de paternité multiple dans toutes les populations de l'étude, réparties dans l'aire de distribution européenne de l'espèce. Le nombre de pères par fruit varie de un à neuf, avec un nombre moyen de trois, ce qui signifie que la paternité multiple est très répandue dans les populations naturelles. En raison de ces résultats, je me suis demandée si le génotype de la femelle influence le succès de paternité des mâles. J'ai alors réalisé des pollinisations manuelles sur la base d'un mélange de pollens issus de deux mâles, que j'ai appliqué sur trois femelles (réplicats) présentant différents degrés d'apparentement (deux soeurs. et une femelle étrangère). Il ressort de cette expérience que le génotype de la femelle peut influencer la paternité dans l'une des deux populations étudiées, ce qui pourrait refléter des différences en terme d'histoire des populations. Dans la mesure où ces résultats suggèrent un certain degré de choix chez la femelle, j'ai cherché à savoir si la paternité multiple et la sélection post-pollinisation pouvaient être des moyens d'éviter les croisements consanguins. Dans un premier temps, j'ai évalué la dépression de consanguinité à différentes étapes du cycle de vie chez des descendants issus de croisements à un seul donneur, celui-ci étant alternativement un frère ou un étranger, répliqués sur plusieurs fleurs d'une même plante femelle. Afin d'estimer l'évitement de croisements consanguins, j'ai effectué des croisements dont le pollen était un mélange des deux mâles (frère et étranger), puis j'ai déterminé la paternité dans les fruits obtenus. J'ai pu mettre en évidence un effet de dépression de consanguinité- significatif dans les populations étudiées, même dans des conditions expérimentales moins rudes qu'à l'extérieur. Bien que le mâle étranger n'ait pas engendré un nombre significativement plus important de graines, il y avait un effet de dissimilarité génétique sur la paternité. Ceci suggère que la paternité est affectée par le degré d'apparentement entre les partenaires, mais qu'elle peut aussi être affectée par d'autres facteurs tels que la compétitivité du pollen ou encore par les interactions mâles-femelles. L'utilisation de croisements consanguins et hybrides m'a également permis d'étudier l'héritabilité du biais de sex ratio chez cette espèce. Il s'est avéré que le biais de sex ratio de la génération parentale était significativement corrélé au succès de germination du pollen de la génération F2, ce qui signifie que, chez cette espèce, le biais de sex ratio résulte d'une combinaison spécifique de X/Y et non uniquement de la performance de Y. Un effet de X et Y est compatible avec l'hypothèse de distorsion de ségrégation méiotique des chromosomes sexuels. En conclusion, il ressort de mes résultats que la paternité multiple est un phénomène largement répandu chez S. latifolia et la paternité accomplie par un mâle est plus similaire entre soeurs qu'avec une femelle étrangère J'ai également mis en évidence que la dépression de consanguinité a un impact considérable; aussi, recevoir du pollen de plusieurs donneurs différents pourrait permettre à la femelle de produire moins de descendants consanguins. J'ai aussi trouvé un effet de la dissimilarité génétique sur le partage de paternité, ce qui indique que la discrimination contre le pollen d'apparentés est possible, bien que cela ne semble pas être le seul facteur déterminant dans le résultat de la paternité. Enfin, j'ai trouvé que le biais de sex ratio est dépendant des deux chromosomes X et Y, conformément à la théorie de distorsion de ségrégation méiotique des chromosomes sexuels.

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The effect that plants {Typha latifolia) as well as root-bed medium physical and chemical characteristics have on the treatment of primary treated domestic wastewater within a vertical flow constructed wetland system was investigated. Five sets of cells, with two cells in each set, were used. Each cell was made of concrete and measured 1 .0 m X 1 .0 m and was 1.3 m deep. Four different root-bed media were tested : Queenston Shale, Fonthill Sand, Niagara Shale and a Michigan Sand. Four of the sets contained plants and a single type of root-bed medium. The influence of plants was tested by operating a Queenston Shale set without plants. Due to budget constraints no replicates were constructed. All of the sets were operated independently and identically for twenty-eight months. Twelve months of data are presented here, collected after 16 months of continuous operation. Root-bed medium type did not influence BOD5 removal. All of the sets consistently met Ontario Ministry of Environment (MOE) requirements (<25 mg/L) for BOD5 throughout the year. The 12 month average BOD5 concentration from all sets with plants was below 2.36 mg/L. All of the sets were within MOE discharge requirements (< 25 mg/L) for suspended solids with set effluent concentrations ranging from 1.53 to 14.80 mg/L. The Queenston Shale and Fonthill Sand media removed the most suspended solids while the Niagara Shale set produced suspended solids. The set containing Fonthill Sand was the only series to meet MOE discharge requirements (< Img/L) for total phosphorus year-round with a twelve month mean effluent concentration of 0.23 mg/L. Year-round all of the root-bed media were well below MOE discharge requirements (< 20mg/L in winter and < 10 mg/L in sumnner) for ammonium. The Queenston Shale and Fonthill Sand sets removed the most total nitrogen. Plants had no effect on total nitrogen removal, but did influence how nitrogen was cycled within the system. Plants increased the removal of suspended solids by 14%, BOD5 by 10% and total phosphorus by 22%. Plants also increased the amount of dissolved oxygen that entered the system. During the plant growing season removal of total phosphorus was better in all sets with plants regardless of media type. The sets containing Queenston Shale and Fonthill Sand media achieved the best results and plants in the Queenston Shale set increased treatment efficiency for every parameter except nitrogen. Vertical flow wetland sewage treatment systems can be designed and built to consistently meet MOE discharge requirements year-round for BOD5, suspended solids, total phosphorus and ammonium. This system Is generally superior to the free water systems and sub-surface horizontal flow systems in cold climate situations.

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Com o objetivo de determinar a eficiência da ação polinizadora de Apis mellifera L. no rendimento de sementes de Adesmia latifolia, estabeleceu-se três tratamentos na Estação Experimental Agronômica da UFRGS, em Eldorado do Sul (300 S, 510 W) nos anos de 2000, 2001 e 2002. A partir da floração, analisou-se a freqüência de visitas por A. mellifera e outros insetos nas flores de A. latifolia pelo teste de Qui-quadrado, já o número de inflorescências por área, número de flores, flores abortadas e lomentos por inflorescência foi através da análise de regressão. Os resultados indicaram que A. mellifera não é eficiente na polinização de A. latifolia, sendo esta cultura dependente de insetos nativos como Megachile sp. e Centris sp para produção de sementes. A média de produção de sementes na área controlada e livre foi 5,4 e 83,5 kg/ha, respectivamente, enquanto na área isolada não houve produção de sementes. A baixa freqüência (10%) de visitas de A. mellifera na área livre em comparação com os insetos nativos (90%) indica que o néctar não é atrativo para as abelhas A. mellifera pois tem uma baixa concentração de açúcares totais (5,7%).

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A floração nos citros, assim como em outras fruteiras, é um dos fatores determinantes para a produção. A possibilidade de inibição ou redução da florada normal e alteração da época de produção para a lima 'Tahiti' é fator primordial para determinar sua rentabilidade econômica. O presente trabalho teve como objetivo avaliar o efeito do ácido giberélico sobre a florada, número de flores formadas, da lima ácida 'Tahiti', nas condições do Estado de São Paulo durante dois anos, buscando inibir a florada normal e observar o efeito desta inibição sobre produções temporãs. O delineamento experimental foi em blocos casualizados (5 blocos) com 3 plantas por tratamento. Foi utilizada uma planta como bordadura entre os tratamentos e uma linha de plantas entre os blocos. Os tratamentos foram: testemunha, 20, 40 e 80 mg/L de ácido giberélico (AG3) + 10 ml/L de espalhante adesivo, e o pH da água utilizada foi 6,2. As plantas foram tratadas com ácido giberélico durante o inverno (estação seca) após 50 dias sem irrigação no primeiro ano e 60 dias no segundo. O ácido giberélico reduziu o número de flores formadas (-81%) e aumentou a produção de frutos temporões (+59,77% ou +16,04 kg/pl).