Pollen viability and germination in some neotropical aroids

Botany ◽  
2008 ◽  
Vol 86 (1) ◽  
pp. 98-102 ◽  
Author(s):  
Denis Barabé ◽  
Karine Lavallée ◽  
Marc Gibernau
Keyword(s):  
Pollen Viability ◽  
Pollen Grains ◽  
Total Loss ◽  
Small Pollen

Pollen viability and germination were observed in six species of neotropical Araceae. In Anaphyllopsis americana (Engl.) A. Hay, 50% of pollen grains remain viable after 70 h following dehiscence, and it takes over 210 h for total loss of viability to occur. In Montrichardia arborescens (L.) Schott, approximately 50% of pollen grains are not viable after 24 h, and no germination occurs after 36 h. Monstera adansonii Schott and Philodendron pedatum (Hook.) Kunth have the lowest initial pollen viability (40%–55%) and lose half of this viability after approximately 30 h. Pollen grains of Monstera adansonii remain viable for at least 60 h and that of P. pedatum for approximately 40 h, and constitute another group with a similar viability pattern. In Philodendron melinonii Brongn. ex Regel and Philodendron solimoesense A.C. Sm., pollen loses 50% of its viability after 24 h, but remains viable for at least 48 h. The percentage of viability decreases in a pattern from species having a long flowering cycle and small pollen grains (A. americana) to species with a short flowering cycle and large pollen grains (M. arborescens).

scholarly journals A Duplicated Copy of the Meiotic Gene ZIP4 Preserves up to 50% Pollen Viability and Grain Number in Polyploid Wheat

Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 290
Author(s):  
Abdul Kader Alabdullah ◽  
Graham Moore ◽  
Azahara C. Martín
Keyword(s):  
Pollen Viability ◽  
Pollen Grains ◽  
Wheat Chromosome ◽  
Grain Number ◽  
Meiotic Gene ◽  
Chromosome 5B ◽  
Mutant Pollen ◽  
Female Gametogenesis ◽  
Chromosome 3B

Although most flowering plants are polyploid, little is known of how the meiotic process evolves after polyploidisation to stabilise and preserve fertility. On wheat polyploidisation, the major meiotic gene ZIP4 on chromosome 3B duplicated onto 5B and diverged (TaZIP4-B2). TaZIP4-B2 was recently shown to promote homologous pairing, synapsis and crossover, and suppress homoeologous crossover. We therefore suspected that these meiotic stabilising effects could be important for preserving wheat fertility. A CRISPR Tazip4-B2 mutant was exploited to assess the contribution of the 5B duplicated ZIP4 copy in maintaining pollen viability and grain setting. Analysis demonstrated abnormalities in 56% of meiocytes in the Tazip4-B2 mutant, with micronuclei in 50% of tetrads, reduced size in 48% of pollen grains and a near 50% reduction in grain number. Further studies showed that most of the reduced grain number occurred when Tazip4-B2 mutant plants were pollinated with the less viable Tazip4-B2 mutant pollen rather than with wild type pollen, suggesting that the stabilising effect of TaZIP4-B2 on meiosis has a greater consequence in subsequent male, rather than female gametogenesis. These studies reveal the extraordinary value of the wheat chromosome 5B TaZIP4-B2 duplication to agriculture and human nutrition. Future studies should further investigate the role of TaZIP4-B2 on female fertility and assess whether different TaZIP4-B2 alleles exhibit variable effects on meiotic stabilisation and/or resistance to temperature change.

Incompatibility, stamen movement and pollen economy in a heterostyled tropical forest tree, Cratoxylum formosum (Guttiferae)

1982 ◽  
Vol 214 (1195) ◽  
pp. 273-283 ◽  
Keyword(s):  
Critical Level ◽  
Pollen Grains ◽  
Forest Tree ◽  
Incompatible Pollen ◽  
Insect Visitation ◽  
Small Pollen ◽  
Evolutionary Step ◽  
Novel Method ◽  
Compatible Pollinations ◽  
Compatible Pollen

Cratoxylum formosum shows all the classical features of a distylic species. The two types are: long-styled plants with short stamens and small pollen grains and short-styled plants with long stamens and large pollen grains. Compatible pollinations are only between the two types; incompatible pollen tubes are inhibited in the style. A significant morphological feature distinguishes Cratoxylum from distylic plants in other families. Instead of having a small number of anthers making well separated narrow discs in the two types, Cratoxylum has many anthers (144) and they are arranged on staminal bundles that produce long cylinders of anthers that partially occupy similar height zones in the two types of flower. A novel method of separation of the two height zones is achieved by the bending of the stamens of the long-styled type when the flower opens, which converts the cylinder to a narrow disc of anthers at the same height as the ‘short’ stigma. The bending coincides with anther dehiscence and is slightly later than the first daily insect visitation. The anthers return to the upright position later in the day, when the pollination is complete. There was a 20-fold difference between the amounts of pollen deposited on the two types of stigmas. The ‘long’ stigmas received 1200 pollen grains per flower, in the ratio of 46 ‘long’ to 54 ‘short’, which is close to the ratio of two types of pollen produced in the population. This random deposition of pollen on ‘long’ stigmas is, however, more than adequate for the 36 seeds produced per flower. ‘Short’ stigmas received only 64 pollen grains per flower, in the ratio of 90 ‘long’ to 10 ‘short’, and several flowers had below the critical level of 36 compatible pollen grains for full seed production. Pollen loads of the pollinating bee, Apis javana , consisted of ‘long’ and ‘short’ pollen on the thorax in the ratio found on the ‘long’ stigma, and on the head of the bee in a ratio close to the 9:1 found on the ‘short ’ stigma. The corbicular loads reflected accurately the pollen of the tree in which the bee was caught. For Cratoxylum the accurate positioning of the anthers of the long-styled plant in relation to the visiting bees head was an important evolutionary step in the effective pollination of the short-styled form, which, at least in this species, is one critical and highly selected feature of the system.

Effect of growth substances on the expression of flowering and study on pollen viability of hermaphrodite & male ower in the female clone “Mondouri local” of Teasle gourd (Momordica subangulata Blume. subsp. renigera)

2019 ◽  
Vol 8 (2) ◽  
pp. 63-66
Author(s):  
Abhishek Naik ◽  
Shirin Akhtar ◽  
Arup Chattopadhyay ◽  
Umesh Thapa ◽  
Pranab Hazra
Keyword(s):  
Gibberellic Acid ◽  
Pollen Tube ◽  
Silver Nitrate ◽  
Pollen Viability ◽  
Pollen Size ◽  
Normal Male ◽  
Growth Substances ◽  
Flowering Stage ◽  
Foliar Sprays ◽  
Small Pollen

Foliar sprays with gibberellic acid (GA) and silver nitrate (AgNO3) of di erent concentra ons at pre-flowering stage induced hermaphrodite and male owers on strictly gynoecious vines of teasle gourd (Momordica subangulata Blume. subsp. renigera). GA at 1500 ppm and AgNO3at 500 ppm were effective inducing more than 50% male owers in the female clone “Mondouri local”. AgNO3 at 750 ppm was effective in inducing 36.6% male and 33.9% hermaphrodite owers on same plant. The hermaphrodite ower had higher pollen size (103.57 μm) compared to that of natural male ower (94.94 μm). However, there existed no variation between pollen viability of bisexual ower (81.6%) and normal male ower (89.1%). However, germinability of the pollen of hermaphrodite ower was very low (14.16%) producing very small pollen tube (9 μm), though the bisexual ower did not produce any fruit on self-pollination.

Virola dominicana sp. nov. (Myristicaceae) from Dominican amber

Botany ◽  
2013 ◽  
Vol 91 (8) ◽  
pp. 530-534 ◽  
Author(s):  
George Poinar ◽  
Royce Steeves
Keyword(s):  
New Species ◽  
Intraspecific Variation ◽  
Pollen Grains ◽  
First Record ◽  
Western Hemisphere ◽  
Dominican Amber ◽  
The Family ◽  
Small Pollen ◽  
Male Flowers ◽  
Staminal Column

The Myristicaceae is a member of the early diverging angiosperm order Magnoliales; however, the family is poorly represented by fossil collections. We describe Virola dominicana sp. nov. (Myristicaceae), the first record of fossilized Myristicaceae flowers, from mid-Tertiary (45–15 million years ago) Dominican amber. The description is based on 24 male flowers in 17 pieces of amber, thus providing some indication of intraspecific variation, including a two-tepaled flower. Diagnostic characters of the new species are the long-simple or few-branched trichomes on the perianth margins, the small pollen grains, and a short staminal column. These fossils also show co-occurring insects, some of which could be Virola pollinators. It is speculated that V. dominicana disappeared from Hispaniola during the Pliocene–Pleistocene cooling events leaving no native members of the Myristicaceae in this region today. Additionally, these fossils demonstrate that Myristicaceae was present in the Western Hemisphere during the mid-Tertiary.

scholarly journals Biology of Flowering, Fruit and Viability of Pollen of Varieties and Forms of Quince Cultivated on the Territory of the Nakhchivan Autonomous Republic

2021 ◽  
Vol 7 (3) ◽  
pp. 64-69
Author(s):  
L. Bayramov
Keyword(s):  
Pollen Fertility ◽  
Pollen Germination ◽  
Glucose Solution ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Weather Conditions ◽  
Distilled Water ◽  
Water Control ◽  
Germinated Pollen ◽  
Autonomous Republic

Abstract. The zones of distribution of varieties and forms of quince on the territory of the Nakhchivan Autonomous Republic have been established, phenological observations have been carried out, their flowering and fruiting have been studied. On the territory of the Autonomous Republic, flowering of varieties and forms of quince begins in the second decade of April, depending on the distribution zone, with an average daily temperature of 12–13 °C and lasts 12–13 days, depending on weather conditions. Each flower has 10–12 stamens arranged in one row. The article also studied the viability of pollen in a number of quince varieties. Pollen viability was studied in the varieties Sary, Tursh, Ordubad, Gara and wild forms. Pollen fertility was determined by staining with acetocarmine. Pollen germinates in 2–5–10–15 and 20% glucose solution. Counting of germinated pollen grains was carried out under a microscope. The study showed that of all the experimental varieties, the pollen fertility of the Sary quince and Tursh quince varieties is high (up to 96.6–97.1%). The best medium for the germination of quince pollen is a 10–15% glucose solution. Pollen germination in this solution reaches 47.4–88.0%. In distilled water (control), the germination of quince pollen reached from 9.7% to 35.6% for varieties. Quince pollen remains viable for 31–43 days.

scholarly journals Flowering Biology of Rhododendron pulchrum

Horticulturae ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 508
Author(s):  
Jie Qiu ◽  
Chao Gao ◽  
Hongli Wei ◽  
Biao Wang ◽  
Yang Hu ◽  
...  
Keyword(s):  
Colorimetric Assay ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Experimental Period ◽  
Polar Axis ◽  
Flowering Phenology ◽  
Mtt Colorimetric Assay ◽  
Single Flower ◽  
Axis Length ◽  
To Receive

To study the flowering biology of Rhododendron pulchrum, we used scanning electron microscopy (SEM) and paraffin sectioning to observe the microstructures of its floral organs, a methyl thiazolyl tetrazolium (MTT) colorimetric assay to detect pollen viability in different periods, continuous observations to study flowering phenology, and artificial pollination and a benzidine-hydrogen peroxide method to determine stigma receptivity. R. pulchrum exhibited a centralized flowering phenology. The protogynous stigmas of R. pulchrum were able to receive pollen before flowering. The pollen grains of R. pulchrum fused into tetrads, the average ratio of the polar axis length to the equatorial axis length (P/E) was 1.05, and the pollen viability was highest in the initial flowering period, reaching 88.98%. The pollen/ovule (P/O) ratio was 266–328, and the outcrossing index (OCI) was 4; the vitality of R. pulchrum pollen remained high in the initial flowering and blooming periods. Compared with the lifespan of a single flower, pollen vitality remained high for most of the experimental period, thereby improving male fitness. The P/O ratio suggests that R. pulchrum may have a facultative outcrossing breeding system. The OCI estimation suggests that R. pulchrum is partially self-compatible, most likely requiring pollinators to complete pollination.

scholarly journals Reproductive characterization of interspecific hybrids among Capsicum species

2011 ◽  
Vol 11 (3) ◽  
pp. 241-249 ◽  
Author(s):  
Carlos Eduardo da Silva Monteiro ◽  
Telma Nair Santana Pereira ◽  
Karina Pereira de Campos
Keyword(s):  
Male Sterility ◽  
Interspecific Hybrids ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Male Sterile ◽  
Viable Pollen ◽  
Hybrid Combination ◽  
Capsicum Species ◽  
The Cross

The objective of this study was the reproductive characterization of Capsicum accessions as well as of interspecific hybrids, based on pollen viability. Hybrids were obtained between Capsicum species. Pollen viability was high in most accessions, indicating that meiosis is normal, resulting in viable pollen grains. The pollen viability of species C. pubescens was the lowest (27 %). The interspecific hybrids had varying degrees of pollen viability, from fertile combinations (C. chinense x C. frutescens and C. annuum x C. baccatum) to male sterile combinations. Pollen viability also varied within the hybrid combination according to accessions used in the cross. Results indicate that male sterility is one of the incompatibility barriers among Capsicum species since hybrids can be established, but may be male sterile.

scholarly journals Effect of high temperature on the reproductive development of chickpea genotypes under controlled environments

2012 ◽  
Vol 39 (12) ◽  
pp. 1009 ◽  
Author(s):  
Viola Devasirvatham ◽  
Pooran M. Gaur ◽  
Nalini Mallikarjuna ◽  
Raju N. Tokachichu ◽  
Richard M. Trethowan ◽  
...  
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Pollen Germination ◽  
Pollen Viability ◽  
Pollen Grains ◽  
High Temperature Stress ◽  
Pollen Production ◽  
Seed Number ◽  
Controlled Environments

High temperature during the reproductive stage in chickpea (Cicer arietinum L.) is a major cause of yield loss. The objective of this research was to determine whether that variation can be explained by differences in anther and pollen development under heat stress: the effect of high temperature during the pre- and post-anthesis periods on pollen viability, pollen germination in a medium, pollen germination on the stigma, pollen tube growth and pod set in a heat-tolerant (ICCV 92944) and a heat-sensitive (ICC 5912) genotype was studied. The plants were evaluated under heat stress and non-heat stress conditions in controlled environments. High temperature stress (29/16°C to 40/25°C) was gradually applied at flowering to study pollen viability and stigma receptivity including flower production, pod set and seed number. This was compared with a non-stress treatment (27/16°C). The high temperatures reduced pod set by reducing pollen viability and pollen production per flower. The ICCV 92944 pollen was viable at 35/20°C (41% fertile) and at 40/25°C (13% fertile), whereas ICC 5912 pollen was completely sterile at 35/20°C with no in vitro germination and no germination on the stigma. However, the stigma of ICC 5912 remained receptive at 35/20°C and non-stressed pollen (27/16°C) germinated on it during reciprocal crossing. These data indicate that pollen grains were more sensitive to high temperature than the stigma in chickpea. High temperature also reduced pollen production per flower, % pollen germination, pod set and seed number.

scholarly journals A cytogenetic and pollen study of annual Medicago species from Soummam Valley (Northeastern of Algeria)

2019 ◽  
Vol 78 (1) ◽  
pp. 82-90 ◽  
Author(s):  
Linda Djafri-Bouallag ◽  
Malika Ourari ◽  
Mohamed Sahnoune
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Cytogenetic Study ◽  
Pollen Viability ◽  
Pearson Correlation ◽  
Pollen Grains ◽  
Pollen Size ◽  
Relative Standard ◽  
Medicago Littoralis ◽  
Annual Medicago

Abstract This paper reports a cytogenetic study of eight Medicago L. species sampled from the Soummam Valley (northeastern Algeria). Chromosome numbers and meiosis irregularities during microsporogenesis were explored. Pollen viability rate and pollen size were also examined. The studied taxa are diploid and display biva-lent pairing and regular chromosome segregation during meiosis. Although meiosis appears regular, some anomalies were detected in relatively high cumulated rates (14.66%–26.14%). The most common meiotic abnormality examined here is related to cytomixis (from 14.66% in M. littoralis to 25.83% in M. laciniata). Other anomalies were also detected, including chromatic bridges, asynchronous divisions, micronuclei and multipolar cells. Consequently, the species exhibited varying percentages of pollen viability (from 70.11% in M. laciniata to 99.14% in M. littoralis). Pollen viability was negatively correlated with meiotic abnormalities (Pearson correlation coefficient R = −0.72, p = 0.043). The pollen grains were also heterogeneous in size. Medicago truncatula Gaertn. and M. laciniata (L.) Miller presented the most variable pollen size (relative standard deviation exceeding 19%). Medicago littoralis is distinguished from other species by possessing homogeneous and large sized pollen (relative standard deviation RSD = 6.73 %). The cytogenetic and pollen data provided by this study are discussed in the context of species systematics and in the perspective of genetic improvement.

scholarly journals Factors Influencing Cross Barriers in Interspecific Hybridizations of Water Lily

2018 ◽  
Vol 143 (2) ◽  
pp. 130-135 ◽  
Author(s):  
Chunqing Sun ◽  
Zhihu Ma ◽  
Zhenchao Zhang ◽  
Guosheng Sun ◽  
Zhongliang Dai
Keyword(s):  
Pollen Viability ◽  
Pollen Grains ◽  
Endosperm Development ◽  
The Self ◽  
Water Lily ◽  
Tropical Water ◽  
Factors Influencing ◽  
Pollen Germinability ◽  
Germinated Pollen ◽  
Nymphaea Odorata

In interspecific hybridizations of water lily (Nymphaea), the existence of cross barriers makes it difficult to obtain hybrids and seriously influences the utilization of admirable characters from tropical water lilies. To determine the causes, pollen viability, pistil receptivity, and embryo and endosperm development were investigated in three water lily crosses, including Nymphaea odorata ‘Peter Slocum’ × Nymphaea micranthar (PM), ‘Peter Slocum’ × Nymphaea gigantea (PH), and ‘Peter Slocum’ × Nymphaea colorata (PC). The results indicated that the viability of pollen grains was 17.3% for ‘Peter Slocum’, 19.3% for N. colorata, 10.3% for N. micrantha, and 17.6% for N. gigantea. In the self-pollinated ‘Peter Slocum’, the number of germinated pollen grains on stigmas peaked at 12 hours after pollination (HAP), indicating its good pollen germinability. However, only a few pollen grains germinating on the sigma between 2 and 24 HAP in the crosses of PM, PH, and PC. In addition, a high percentage (81.2%) of normal embryos developed to different stages within 20 d after pollination in the self-pollinated ‘Peter Slocum’. But only 3.5% and 3.7% of normal globular embryos were observed in the PC and PM combinations, respectively. Moreover, no normal embryos were observed in the PH cross. At the same time, no seeds were obtained in PM, PC, and PH crosses. The results suggest that prefertilization barriers existed in the PH cross, whereas pre- and postfertilization barriers existed together in the PC and PM crosses. These may be the main causes resulting in the failure of interspecific hybridizations in water lily.

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