Availability of floral resources in yellow passion fruit cultivars

The reproductive strategies and resources available in the flower are characteristics that stimulate research studies on the genetic improvement and fruit yield of commercial cultivars. In this sense, this study aimed to study the floral biology aspects of passion fruit cultivars in Tangará da Serra region, Mato Grosso State, Brazil at different evaluation times. The experiment was carried out with eight cultivars of yellow passion fruit from an ex situ germplasm bank of the State University of Mato Grosso. The floral resources (pollen and nectar) were evaluated in a completely randomized, factorial arrangement (8 cultivars x 5 evaluation times), with five replications. Throughout anthesis, the pollen viability, stigma receptivity, and sugar volume and concentration in the nectar were evaluated. The evaluations were carried out in 1-h intervals, between 1:30 and 5:30 p.m. The highest nectar volume production was at 2:30 p.m., decreasing gradually thereafter at the later evaluation times, for all cultivars. Pollen viability increased from the first to the second evaluation time and then decreased gradually until the last evaluation. Stigma receptivity was higher than 90% in all cultivars, at all evaluation times. BRS Rubi do Cerrado and FB 200 were the most promising cultivars for nectar volume and concentration, pollen viability, and stigma receptivity characteristics.The reproductive strategies and resources available in the flower are characteristics that stimulate research studies on the genetic improvement and fruit yield of commercial cultivars. In this sense, this study aimed to study the floral biology aspects of passion fruit cultivars in Tangará da Serra region, Mato Grosso State, Brazil at different evaluation times. The experiment was carried out with eight cultivars of yellow passion fruit from an ex situ germplasm bank of the State University of Mato Grosso. The floral resources (pollen and nectar) were evaluated in a completely randomized, factorial arrangement (8 cultivars x 5 evaluation times), with five replications. Throughout anthesis, the pollen viability, stigma receptivity, and sugar volume and concentration in the nectar were evaluated. The evaluations were carried out in 1-h intervals, between 1:30 and 5:30 p.m. The highest nectar volume production was at 2:30 p.m., decreasing gradually thereafter at the later evaluation times, for all cultivars. Pollen viability increased from the first to the second evaluation time and then decreased gradually until the last evaluation. Stigma receptivity was higher than 90% in all cultivars, at all evaluation times. BRS Rubi do Cerrado and FB 200 were the most promising cultivars for nectar volume and concentration, pollen viability, and stigma receptivity characteristics

Secondary pollen presentation and foral traits of Heliconia psittacorum

The secondary presentation of pollen consists of a foral mechanism where the presentation of pollen occurs in other foral structures in addition to the anther, in order to increase the precision of the dispersion of the pollen by the vectors. This study aims to describe the temporal dynamics of secondary pollen presentation, and morphological and morphometric characteristics in stages of pre- anthesis and anthesis in genotypes of fve natural Heliconia psittacorum populations. For the study of foral morphometry traits of length of the fower, stamen, stigma and height of flament insertion in the petal in bud and fower were measured. The foral morphology of pre-anthesis buds and fowers in anthesis, the presence or absence of characteristics such as herkogamy, region of flament insertion in the petal, region of stylar hairs, and of secondary pollen deposition were evaluated. Treatments of controlled pollinations, self-pollination, geitonogamy, cross-pollination, natural pollination and growth to pollen tube were sampled. Floral herkogamy and pollen transfer to the adhered hairs in the stylar region were clearly observed during anthesis, constituting the frst record of occurrence of secondary pollen presentation in Heliconiaceae. Pollen tube growth was inhibited in the stigmatic, style and basal regions of the pistil. Natural fruiting produced little or no fruit. The positioning of the stamens above the stigma, pollen viability and stigma receptivity during anthesis of H. psittacorum fowers may favor self-pollination. The stylar hairs observed in all H. psittacorum populations’ help in the retention of pollen grains. The low fruiting rate in controlled and natural pollinations suggest that the main propagation form of H. psittacorum in the study areas is based on asexual reproduction

Morphological and molecular characterization of native Heliconia sp. accessions of the Amazon region

Heliconias are tropical plants with ornamental potential. These plants are particularly used in the floriculture industry because of their exotic colors and shapes. Species characterization is important for the selection of genotypes for the ornamental plant market and subsequent application in studies of genetic improvement. The aim of this study was to estimate the genetic divergence of Heliconia densiflora and Heliconia psittacorum accessions based on quantitative morphological and molecular markers. The mor- phological and molecular descriptors revealed genetic variability among the accessions evaluated. The greatest genetic variability was observed among H. psittacorum accessions, whose sample number was also larger compared to H. densiflora. Morphological characterization was efficient in differentiating the two Heliconia species, especially to characteristics such as bract and inflores- cence length, postharvest durability, and flower stem diameter, which contributed most to the divergence in this study. On the other hand, molecular characterization identified one H. densiflora individual that was grouped with the H. psittacorum genotypes. The results showed that ISSR markers can differentiate closely related H. densiflora and H. psittacorum individuals. The materials evaluated can contribute to the maintenance of local genetic diversity through the germplasm bank of the local breeding program of ornamental tropical plants

Características florais e polinizadores na qualidade de frutos de cultivares de maracujazeiro‑azedo

The objective of this work was to determine the floral traits of eight cultivars of sour passion fruit and identify their pollinators, as well as to evaluate the influence of natural pollination on fruit quality, in the region of Tangará da Serra, MT, Brazil. A completely randomized experimental design was carried out, with ten replicates and one flower per plot to evaluate morphometry, and with four replicates and five flowers per cultivar to determine the fruiting rate. The following parameters were evaluated: flower morphology and morphometry, flower longevity, frequency of floral visitors, natural fruiting rate, and fruit quality. Flower morphology and morphometry were compatible with pollination by large-size bees; they were also compatible with pollination by medium‑size bees for the cultivars IAC‑275‑Maravilha, IAC‑277‑Jóia, BRS SC1, BRS RC, and BRS GA1. The greatest flower longevity was observed for the IAC‑277‑Jóia, BRS GA1, BRS RC, and BRS OV1 cultivars. The frequency of bees as Xylocopa (2.0%) and Bombus (3.9%) was low, and 'BRS GA1' received the highest number of these bee visits. Natural fruiting rate was low (36.67%). Naturally pollinated fruit show physical traits compatible with those required by the market standards.O objetivo deste trabalho foi determinar as características florais de oito cultivares de maracujazeiro‑azedo e identificar seus polinizadores, bem como avaliar a influência da polinização natural na qualidade dos frutos, na região de Tangará da Serra, MT. Utilizou-se o delineamento inteiramente casualizado, com dez repetições e uma flor por parcela para avaliar a morfometria, e com quatro repetições e cinco flores por cultivar para determinar o índice de frutificação. Avaliaram-se os seguintes parâmetros: morfologia e morfometria floral, longevidade floral, frequência de visitantes florais, índice de frutificação natural e qualidade de fruto. A morfologia e a morfometria das flores foram compatíveis com a polinização por abelhas de grande porte; também foram compatíveis com a polinização por abelhas de médio porte nas cultivares IAC‑275‑Maravilha, IAC‑277‑Jóia, BRS SC1, BRS RC e BRS GA1. A maior longevidade floral foi observada nas cultivares IAC‑277‑Jóia, BRS GA1, BRS RC e BRS OV1. A frequência de abelhas como Xylocopa (2,0%) e Bombus (3,9%) foi baixa, e 'BRS GA1' recebeu o maior número de visitas destas abelhas. O índice de frutificação natural foi baixo (36,67%). Os frutos de polinização natural apresentam características físicas compatíveis com as exigidas pelo mercado consumidor

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio