Pistillate Flowers Research Articles

Hermaphroditism in Marijuana (Cannabis sativa L.) Inflorescences - Impact on Floral Morphology, Seed Formation, Progeny Sex Ratios, and Genetic Variation.

Cannabis sativa L. (hemp, marijuana) produces male and female inflorescences on different plants (dioecious) and therefore the plants are obligatory out-crossers. In commercial production, marijuana plants are all genetically female; male plants are destroyed as seed formation reduces flower quality. Spontaneously occurring hermaphroditic inflorescences, in which pistillate flowers are accompanied by formation of anthers, leads to undesired seed formation; the mechanism for this is poorly understood. We studied hermaphroditism in several marijuana strains with three objectives: (i) to compare the morphological features of this unique phenotype with normal male flowers; (ii) to assess pollen and seed viability from hermaphroditic flowers; and (iii) to assess the effect of hermaphroditism on progeny male:female (sex) ratios and on genetic variation using molecular methods. The morphological features of anthers, pollen production and germination in hermaphroditic flowers and in staminate inflorescences on male plants were compared using light and scanning electron microscopy. Seeds produced on hermaphroditic plants and seeds derived from cross-fertilization were germinated and seedlings were compared for gender ratios using a PCR-based assay as well as for the extent of genetic variation using six ISSR primers. Nei’s index of gene diversity and Shannon’s Information index were compared for these two populations. The morphology of anthers and pollen formation in hermaphroditic inflorescences was similar to that in staminate flowers. Seedlings from hermaphroditic seeds, and anther tissues, showed a female genetic composition while seedlings derived from cross-fertilized seeds showed a 1:1 male:female sex expression ratio. Uniquely, hermaphroditic inflorescences produced seeds which gave rise only to genetically female plants. In PCR assays, a 540 bp size fragment was present in male and female plants, while a 390 bp band was uniquely associated with male plants. Sequence analysis of these fragments revealed the presence of Copia-like retrotransposons within the C. sativa genome which may be associated with the expression of male or female phenotype. In ISSR analysis, the percentage of polymorphic loci ranged from 44 to 72% in hermaphroditic and cross-fertilized populations. Nei’s index of gene diversity and Shannon’s Information index were not statistically different for both populations. The extent of genetic variation after one generation of selfing in the progeny from hermaphroditic seed is similar to that in progeny from cross-fertilized seeds.

Assessment of Yield and Quality Characters in Pumpkin from North East India

Twenty five diverse pumpkin germplasm from North East India were assesed for correlation and path coefficient analysis. Correlation revealed that, characters like number of fruit per plant had significant positive correlation with fruit yield per plant both at genotypic and phenotypic level. Path Coefficient Analysis revealed that, days to first pistillate flower anthesis (1.185) and number of fruits per plant (0.681) had maximum positive direct effect on fruit yield per plant.These are the real independent characters and have maximum contribution towards fruit yield per plant at genotypic level. Whereas at phenotypic level, fruit yield per plant was imposed by number of fruits per plant (0.664) only. From the overall result, the traits like days to first pistillate flower anthesis and numbers of fruits per plant can be utilize for breeding programme to increase fruit yield per plant in pumpkin.

<p><strong><em>Begonia tadungensis </em></strong><strong>(<em>Begonia </em>sect. <em>Platycentrum</em>), a new species from southern Vietnam</strong></p>

We here describe and illustrate Begonia tadungensis (B. sect. Platycentrum), a new species from southern Vietnam. The new species is most similar to B. albopunctata in having broadly ovate leaves, three free styles, 4-loculed ovary, and berry-like fruits with a beaked apex, but differs mainly in having a glabrous abaxial leaf surface (not densely red pubescent), and fruits with gray puberlous hairs (not white papillose). It is also similar to B. pendens in its broadly ovate leaves and monoecious breeding system, but differs in having 6 tepals in the pistillate flowers (not 5) and 4-loculed ovaries (not 3-loculed). Information on ecology, conservation status, and a further comparison of characters with these two similar species is also provided.

Pollination of Bactris guineensis (Arecaceae), a potential economically exploitable fruit palm from the Colombian Caribbean

Regardless of the ecological and economical importance of palms, their pollination strategies and the identities of their true pollinators are still contentious subjects. Bactris guineensis grows in open areas in lowland Caribbean Colombia. Its fruits have long been an important component of local economy and are now targeted for broader scale production for the Colombian market. We explored details of the reproductive biology of B. guineensis in its natural environment to understand the various elements of pollen flow dynamics that ensure optimal fruit yield. During two consecutive years, we investigated the phenology, floral biology and pollination ecology of a wild population of B. guineensis in the department of Sucre, northern Colombia. Monthly production of buds, inflorescences and ripe infructescences were quantified. Pollen carrying capacity, efficiency and fidelity of anthophilous insect species associated with B. guineensis were calculated and used to define their role as effective pollinators. Bactris guineensis is protogynous and exhibits ephemeral nocturnal anthesis. In spite of strict xenogamy the average reproductive success was over 75%, attributed to high pollen vector efficiency. Twenty-seven insect species representing three orders were recorded as floral visitors, but the only effective pollinators were minute flower weevils and sap beetles. At the beginning of the female phase of anthesis, when pistillate flowers are receptive, inflorescences of B. guineensis warm up to over 12 °C above ambient air and emit a balsamic scent, attracting swarms of several hundred to thousands of beetles loaded with pollen. A second, shorter-lasting floral heating event takes place by dusk in the following day (or the male phase), which culminates with pollen shedding of staminate flowers and departure of the pollinators. Anthesis events that are highly synchronized with activity patterns of specialized scent-oriented pollinators ensure the high reproductive success of B. guineensis at our study site. Plans for large scale production should prioritize insect-friendly practices and investigation on the role of volatile floral kairomones for pollinator attraction.

Staminate and pistillate flowers and fruits of Halophila ovalis subsp. bullosa (Setchell) Hartog

Flowers and fruit of the seagrass Halophila ovalis subsp. bullosa (Setchell) Hartog are reported from the Nasese intertidal flats, Laucala Bay, Fiji Islands, and described for the first time. The observation of pistillate and staminate flowers completes the flowering event reporting of this endemic Fijian taxon, and also resolves its taxonomic identity. Lack of prior descriptions of H. ovalis subsp. bullosa flower and fruit may be a consequence of the small size of the flower and fruit structures, which may be easily overlooked during field studies. Our descriptions confirm that H. ovalis subsp. bullosa in Fiji is a dioecious seagrass, and that its reproductive features are identical to those of H. ovalis. The reproductive features observed, therefore, provide no evidence for subspecies designation of H. ovalis subsp. bullosa. Description of the sexual reproductive structures of H. ovalis subsp. bullosa is important in species discrimination, field identification, and to provide further precision in seagrass ecological investigations.

Two new baccate species of Begonia sect. Platycentrum (Begoniaceae) from Vietnam

In North Vietnam, two baccate new species of Begonia in Begoniaceae are described, viz. Begonia pendens and Begonia satelloides. The first new species differs from B. hahiepiana principally in its cylindrical petioles, pistillate flowers with obovate outer petals and lanceolate inner petals, and trigonous-ellipsoid fruits with 2.9‒3.4 length- to width ratio. The second new species differs from B. balansana mainly in the abaxially pubescent leaf surface, cylindrical petioles, broadly ovate leaves, and the fruits with wings. The two new species usually grow under dense non-limestone forests of tropical lowlands and valleys, and face a higher risk of extinction from tropical agricultural practices compared to those neighboring species growing on limestone hills.

Genetic variability in bottle gourd

The present investigation was carried out at Main Experiment Station of Department of Vegetable Science, Narendra Deva University of Agriculture & Technology, Narendra Nagar, (Kumarganj) Ayodhya (U.P.), India during summer season of 2013 in a Randomized Block Design with three replications. Observations were recorded for twelve quantitative characters viz., node to first staminate flower anthesis, node to first pistillate flower anthesis, days to first staminate flower anthesis, days to first pistillate flower anthesis, days to first picking, number of fruits/ plant, fruit weight (kg), fruit length (cm), fruit circumference (cm), vine length at the time of last harvest (m), number of branches/plant, fruit yield (kg/plant). The analysis of variance showed highly significant differences for all the characters studied indicating considerable variability among the genotypes. The highest GCV (63.07%) and PCV (63.75%) were observed for fruit yield (kg/plant). In general PCV was marginally higher than the corresponding GCV indicated the less influence of environment in the expression of the characters under study. The broad sense heritability was high for all characters expected genetic advance as percent of mean was also moderate to high for all the economic traits. Thus, most of the economic characters studied in the present investigation were expected to exhibit satisfactory response through selection.

<p><strong>Reestablishment and recircumscription of <em>Paepalanthus elatus </em>(Eriocaulaceae, Poales), a threatened micro-endemic species from northern Serra do Cipó, Minas Gerais, Brazil</strong></p>

Although described as a distinct species, Paepalanthus elatus is currently considered as a variety of P. argenteus and known only from the type collection. Here, we perform the most comprehensive morphological analysis of P. elatus to date, derived from field and herbaria observations, including morphometry of vegetative and reproductive characters. The results support reestablishment of the taxon at species level. A recircumscription of the taxon is provided based on a complete description. The pistillate flowers are described in detail for the first time. We present notes on phenology, conservation status, and taxonomy, including a second-step lectotypification of the name Paepalanthus elatus, together with detailed photographs of living plants and a distribution map. Paepalanthus elatus is micro-endemic to a district called Fechados, Santana do Pirapama municipality, northern Serra do Cipó, in the Campo Rupestre vegetation of the Espinhaço Range, and should be considered critically endangered according to IUCN criteria. Our recognition of P. elatus as an accepted species raises the number of species of P. subg. Xeractis to 29.

Cold Stratification and Pericarp Removal Improve Seed Germination of Ptelea trifoliata and Ptelea crenulata

Two species of North American shrubs in the genus Ptelea (Rutaceae), commonly known as eastern and western hoptree or wafer ash, have unfulfilled potential to increase the diversity of managed landscapes and support populations of pollinators and swallowtail butterflies. The white flowers of Ptelea are highly fragrant, and pistillate flowers give rise to clusters of distinctive samaras. The insufficiency of information about improving germination of seeds of Ptelea trifoliata and lack of recommendations for Ptelea crenulata prompted us to investigate effects of pericarp removal and cold (4 °C) stratification periods of 0, 4, 8, and 16 weeks on the germination of seeds of these two species. Samaras were collected from multiple plants of both species in the midwestern United States (P. trifoliata) and California (P. crenulata). The germination percentage of viable seeds, calculated after tests of viability with tetrazolium chloride of seeds that did not germinate, increased with longer stratification periods, with 100% germination for P. crenulata and 91% germination for P. trifoliata after 16 weeks of stratification. The germination value, a measure of the speed and uniformity of germination, and peak value also increased with longer stratification in both species. Pericarp removal increased the germination percentage of both species and increased the peak and germination value of P. crenulata. Propagators seeking to grow these species of Ptelea from seed should remove the pericarp and cold-stratify seeds for 16 weeks to improve germination success.

Эффективность микроудобрений для повышения семенной продуктивности и качества семян родиолы розовой в зависимости от условий сезона вегетации

Изучено влияние абиотических факторов среды на прохождение основных фенологических фаз у растений родиолы розовой 2-го, 3-го и 4-го годов вегетации. На 4-й год вегетации количество растений с пестичными цветками составляло 54 %. Используемые бинарные смеси микроудобрений — Силиплант (1 мл/л), Феровит (1,5 мл/л), ЭкоФус (5 мл/л) — в целом заметно повысили не только семенную продуктивность растений родиолы розовой, но и качество семян. Некорневые обработки проводили двукратно: в фазу весеннего отрастания и в фазу начала бутонизации. Наиболее перспективным вариантом обработки оказалась бинарная смесь Силиплант + Феровит. У растений 3-го года вегетации масса 1000 семян превышала контроль (без обработки микроудобрениями) на 19,6 %, у растений 4-го года вегетации — на 33,5 %. В варианте Силиплант + Феровит у растений 4-го года вегетации доля крупных семян увеличилась на 8 % по сравнению с контролем. В данном варианте у растений 3-го и 4-го годов вегетации доля выполненнных семян превышала контроль на 24,1 – 35,9 %. Всхожесть у крупных семян повысилась по сравнению с контролем на 3 – 5 %, у мелких семян — на 4 – 8 %. Энергия прорастания семян увеличилась соответственно на 2 – 5 и 1 – 5 %.

Taxonomic revision of Astraea (Euphorbiaceae)

Astraea is a genus of tribe Crotoneae (Euphorbiaceae: Crotonoideae) widely distributed in the Neotropical region. Its highest diversity is found in eastern Brazil, and a few weedy species were most likely introduced and naturalized in the Paleotropics. Species of Astraea may be recognized by the usually deeply lobed leaves, lacking basilaminar or acropetiolar nectaries; spiciform inflorescence with bisexual cymules at the base and staminate cymules toward the apex; pistillate flowers with a segmented nectary and multifid styles; staminate flowers with an imbricate calyx, petals bearing dense moniliform trichomes at the basal portion of their margin and 11–15 stamens; and usually tetragonal and verrucose seeds, bearing a caruncle. Based on recent advances in the taxonomic and systematic knowledge of Astraea, we present a taxonomic revision of the genus. Thirteen species are recognized based on morphological characters. We present a full review of morphology and geographical distribution of the genus, along with data on ecology, phytochemistry and medicinal uses, gathered from the literature and fieldwork. Along with an identification key to the species, we provide descriptions, illustrations and photographs, as well as etymology and vernacular names, geographical distribution and ecology, conservation status and comments on taxonomic and nomenclatural matters. Fifteen lectotypes and three neotypes are newly designated here.

Development of heterotic hybrid in bitter gourd (Momordica charantia L.) for earliness and high fruit yield

The present investigation was undertaken to study the magnitude of heterosis in 45 hybrids (F1s) developed by following the Line × Tester mating design using fifteen lines and three testers for earliness and high fruit yield. Among the parents, OBGCBR-2 and IC-085611 have performed as superior genotypes for heterosis. Highest degree of heterosis for most of the traits i.e., earliness and fruit yield traits were registered in desired direction in the hybrid OBGCBR-2 × Jaunpuri Green. Estimation of standard heterosis in cross OBGCBR-1 × IC-085611 recorded desired relative heterosis for days to 50% pistillate flowering. Heterosis for node at which 1st pistillate flower appears was in the desired direction in cross OBGCBR-2 × Jaunpuri Green for standard check and; hybrid Meghna × Jaunpuri Green for relative heterosis and heterobeltiosis. Hybrids Katehi × IC-085612 exhibited negative and significant relative heterosis and heterobeltiosis for internodal length. In case of sex ratio and fruit length cross OBGCV-2 × IC-085612 showed heterosis in desired direction for relative parent and heterobeltiosis. The positive and significant, relative parent and heterobeltiosis was in the hybrid Green Jhalari × Jaunpuri Green for fruit diameter. For average fruit weight positive and significant heterosis observed in cross OBGCBR-2 × IC-085611 over standard parent. Estimation of standard heterosis for number of fruit plant-1 indicated that the hybrids OBGCBR-2 × IC-085611 found to be desirable superior cross combinations over standard heterosis followed by Meghna × Jaunpuri Green for relative parent and heterobeltiosis.

Assessment of correlation for yield and its contributing traits in papaya cv. Red Lady Taiwan under South Gujarat conditions

A study was carried out to identify the correlation between vegetative traits, floral characters and yield related attributes with fruit yield and weather parameters in papaya cv. Red Lady Taiwan under South Gujarat conditions at Navsari Agricultural University, Navsari during 2018-19. Results revealed that plant height; stem girth and leaf area had a highly significant and positive correlation with fruit yield in hermaphrodite and pistillate forms of papaya. Yield also expressed a highly significant and positive correlation with insertion height of first fruit in bothviz.,pistillate and hermaphrodite plants. Further, yield attributing characters like number of fruits per plant, fruit weight, fruit diameter and fruit length showed positive and highly significant correlation with yield in both type of plants. With regard to traits like weather parameters, plant height, stem girth and leaf area showed significantly positive correlation with maximum temperature in both the types of plants. Pistillate flowers showed highly significant positive correlation with minimum temperature and barren flowers exhibited highly significant positive correlation with sunshine hours while, misshapen hermaphrodite fruits had a positive and highly significant correlation with maximum temperature. The trait fruit yield showed highly significant positive correlation with minimum temperature and sunshine hours in pistillate and hermaphrodite plants of papaya cv. Red Lady Taiwan.

<p><strong><em>Amaranthus rajasekharii </em></strong><strong>(Amaranthaceae), a new species from Kerala (SW-India)</strong></p>

A new species of Amaranthus from Kerala (SW-India)—Amaranthus rajasekharii—is described and illustrated. Macro- and micro-morphological descriptions (with SEM analysis of pollen and seed), as well as original photos and drawings were provided. The new species is similar to A. dubius, from which it differs by stem color, inflorescence structure, gynoecium colour, number of stamens, and shape and lenght of tepals and bracts in pistillate flowers, seed ornamentation, and pollen architecture.

Gynodioecy in the common spindle tree (Euonymus europaeus L.) involves differences in the asymmetry of corolla shapes between sexually differentiated flowers.

Gynodioecy is typically associated with a smaller perianth size in purely pistillate flowers than in hermaphrodite flowers. However, it is unclear whether this size differentiation is associated with any differences in flower shape between the two sexual groups. A geometric morphometric analysis of the symmetry of tetrameric corolla shapes was used in the study of Euonymus europaeus L., Darwin’s classical system of floral sexual differentiation. I investigated whether there are any shape differences between the female and bisexual flowers, with respect to both purely symmetric variation involving coordinated shape changes of the four petals and asymmetry among petals within flowers. The corolla shapes of the female and bisexual flowers and the variability among flowers within each sexual group were very similar in the purely symmetric components of shape variation. However, the female flowers were significantly more asymmetric with respect to both the lateral and transversal asymmetry of their corolla shapes. This is the first study to apply geometric morphometrics in the analysis of morphological patterns in a sexually differentiated gynodioecious plant system. The results showed that subtle shape differences in corolla asymmetry differ between the sexual groups and indicate diverging developmental or selection signals between the sexes.

Pruned side shoots as planting material: Opening new dimensions for sustainable greenhouse cucumber production system

The study was conceptualized to use pruned side shoots as planting material in greenhouse cucumber production system with 2 sets of experiments, 1st was to study the response of different cultivars to establish plants from side shoot cuttings and 2nd was to carry out the comparative performance of cultivars propagated through seeds and side shoot cuttings. Greenhouse cucumber cultivars showed variable response to propagation with the potential of using pruned side shoots as planting material, however, cv. V2 was earliest to respond for getting side shot cuttings (14.44 days), took minimum days to establishment of transplant (12.22) with maximum survival of pruned shoots (73.11%) and produced maximum number of cuttings for propagation (15.98), while V11 showed maximum survival (93.21%) after transplanting in the field. The comparative study on the performance of different greenhouse cultivars propagated though seeds and pruned shoots showed first pistillate flower at earliest node (5.22) in cultivars raised though pruned side shoots, while maximum vine length (3.87 m), fruit length (15.93 cm), diameter (3.20 cm), and av. fruit weight (136.46 g) was observed in plants cultivated via seeds. Moreover, reproductive parameters like days to first flowering and picking, and yield parameters, namely, number of fruits per plant and yield per plant expressed non-significant differences between plants raised through seeds and side shoots. The interaction of different cultivars with propagation methods revealed significant differences with maximum plant height (4.68 m) in cv. V5, number of fruits (32.94) in V9, average fruit weight (154.74 g) in V8, yield per plant (4.29 kg) in V7 when raised through seeds. However, interaction between cultivar and method of propagation exhibited non-significant differences for days to first flowering & picking, node of first pistillate flower, fruit length & diameter, sensory scoring and yield thereby recommending propagation of greenhouse cucumber cultivars via pruned side shoots for getting not only the comparative yield but also minimizing capital investment on costlier seeds of such cultivars along with higher returns by the sale of extra plants generated through this technique to other greenhouse growers.

Evaluation of genetic variability, heritability and genetic advance in sponge gourd (<em>Luffa cylindrica</em> L. Roem.) for various quantitative traits

The present investigation was carried out at Main Experiment Station, Department of Vegetable Science, Narendra Deva University of Agriculture & Technology, Kumarganj, Faizabad (U.P.) during summer season, to evaluate the available germplasms for yield and its component traits of 30 genotypes, with three replications in Randomized Block Design. The study revealed that the mean sum squares due to genotypes were significant for all the characters, though the wide range of genetic variability in the material. Genetic variability, heritability and genetic advance were studied in 13 genotypes of sponge gourd. The phenotypic coefficient of variations (PCV) was higher than the genotypic coefficients of variations (GCV) for all traits studied, indicating that the apparent variation is not only genetic but also influenced by the growing environment in the expression of the characters. The genotypic coefficients of variation and phenotypic coefficients of variation were moderate to low for all the characters except Vine length(39.53%, 40.09%) followed by node number to anthesis of first staminate flower (33.12%, 34.13%) and lower value days to first marketable fruit harvest (11.79%, 13.28%), days to anthesis of first staminate flower (12.57%, 13.69%) and days to anthesis of first pistillate flower (13.69%, 14.78%).High heritability coupled with high genetic advance was estimated for most of the traits viz., vine length (97.24%, 80.31%), node number to anthesis of first staminate flower (94.21%, 66.23%) and number of fruits per plant (92.49%, 45.65%)thus indicating that these traits had additive gene effect so that, they are more reliable for effective selection.

Sexual types of flowers morphology inHeracleum sibiricum(Apiaceae)

According to the structural features ofHecaleum sibiricumflowers, three sexual types of flowers are distinguished, bisexual, pistillate, and staminate. In pistillate flowers a reduction of androecium and its parts is observed, and a reduction of gynoecium, with the exception of stylopodium there is in staminate flowers. The three sexual types of flowers in a umbellet are significantly distinguished by their size that is decreased in the following row: bisexual – pistillate – staminate. The reasons of such changes are discussed.

Contributions to the Flora of Myanmar V: a new record of Mallotus tokiae (Euphorbiaceae) with the description of flower morphology from Lampi Island

Mallotus tokiae (Euphorbiaceae), a poorly known species, was described based upon a single fruiting specimen from Surat Thani Province, peninsular Thailand. We found this species with staminate and slightly mature pistillate flowers in Lampi Island, Myanmar. A new locality record, description of flowers, preliminary conservation assessment and DNA barcoding of this species are provided.

Basal NPK and top-dressing N fertilizer requirements for improved growth and yield of Cucurbita argyrosperma in South Africa

Cucurbita argyrosperma has edible shoots, flowers, fruits and seeds that are rich in nutrients and minerals. However, it is scarcely grown by local farmers in South Africa. This study aimed at establishing fertilizer requirements for its improved growth and yield under large scale farming. Plants were grown under different quantities of 2: 3: 4 (30) NPK basal fertilizer and nitrogen (LAN at 28% N) top-dressing. Shoots and leaves of C. argyrosperma plants treated with 300 NPK basal fertilizer at varying nitrogen top dressing, grew faster from 42 to 49 days after planting (DAP). Plants treated with the same fertilizer combinations had thicker stems, numerous leaves, higher leaf total chlorophyll content, heavier fresh shoots, numerous staminate and pistillate flowers, at 49 DAP. At harvest, the same fertilizer treatments resulted in higher number, mass and size of fruits and seeds. The majority of traits had positive correlation amongst each other but shoot moisture content correlated negatively with all traits. Almost all traits were positively defined in both principal component analysis and scatter plot. In a scatter plot, fertilizer treatments grouped themselves based on NPK basal fertilizer, with 300 NPK fertilizer at varying nitrogen being defined positively.