scholarly journals Pollen productivity and morphology of pollen grains in two cultivars of honeyberry (Lonicera kamtschatica (Sevast.) Pojark.)

2012 ◽  
Vol 60 (1) ◽  
pp. 73-77 ◽  
Author(s):  
Małgorzata Bożek

In the years 2004-2006, investigations on the abundance of pollen production in two cultivars of <i>Lonicera kamtschatica</i> (Sevast.) Pojark. - Atut and Duet, were conducted at the Felin Experimental Farm of the Agricultural University in Lublin. Moreover, the viability of pollen grains was estimated and measurements of their size were taken. Ten flowers of both studied cultivars supplied 11.42 mg of pollen and the average pollen productivity per 1 ha of a several-years-old plantation was 30.04 kg. The pollen of the observed plants was eagerly collected by honey bees. Pollen grains of both cultivars are suboblate. Considering their size, they can be described as large ones (P=47.55 µm, E=60.37 µm). Pollen viability for both cultivars is high, about 95%.

2012 ◽  
Vol 39 (12) ◽  
pp. 1009 ◽  
Author(s):  
Viola Devasirvatham ◽  
Pooran M. Gaur ◽  
Nalini Mallikarjuna ◽  
Raju N. Tokachichu ◽  
Richard M. Trethowan ◽  
...  

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.


2012 ◽  
Vol 59 (1) ◽  
pp. 99-105
Author(s):  
Beata Żuraw

In the years 1999-2001 the study was carried out in the area of UMCS Botanical Garden in Lublin. Plants of <i>Camassia cusickii</i> S.Wats. and <i>Camassia leichtlinii</i> (Bak.) S.Wats. bloomed in May. During a day peak, of flowering occurred at 17.00 h. All anthers shed pollen simultaneously, just after tepals were expanded. Ten flowers produce 10.6-12.8 mg of pollen. The pollen viability ranged from 58 to 92%. The length of longitudinal equatorial axis (E) in <i>Camassia</i> Lindl. pollen grains reached 57,7 µm.


2012 ◽  
Vol 59 (1) ◽  
pp. 165-175 ◽  
Author(s):  
Marzena Masierowska

This 3-year study examined the seasonal and daily dynamics of blooming, as well as the nectar and pollen production in <i>Geranium sanguineum</i> L. Moreover, the type and localization of floral nectaries were observed using LM and SEM, and measurements of pollen grains were performed. The visitation of insects on flowers was monitored, too. <i>Geranium sanguineum</i> bloomed from the beginning of May until the middle of July with the peak occurring between the second and the fifth week of flowering period. Most of the flower buds opened on plants in the afternoon hours. Flowers are protandrous. In a flower, nectar is secreted by five phanarothetic-discoid nectaries and it flows through modified stomata. It was found that one gland is bigger than the others. Ten flowers produced 30.58 mg of highly concentrated nectar, on average. The mean mass of total sugars secreted in nectar per 10 flowers was 7.94 mg. Pollen mass per 10 flowers was 23.14 mg, on average. Tricolpate, spherical pollen grains can be classified as very big size (sporae permagne). Flowers of <i>G. sanguineum</i> were visited mainly by honey bees, bumble bees and flies. Insects collected mainly nectar.


Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 592
Author(s):  
Noemi Tel Zur ◽  
Ronen Rothschild ◽  
Udi Zurgil ◽  
Yiftach Vaknin

The seeds of the dioecious shrub jojoba (Simmondsia chinensis (Link) Schneider) yield a liquid wax that is in high demand for the cosmetics industry. While elite female cultivars of this species are currently clonally propagated, male plants are grown from seed, resulting in large variations in both the flowering period and the pollen viability, and hence large variation in yields. We characterized the existing male plant material in a local plantation as a platform for future selection of elite male cultivars that would produce sufficient amounts of viable pollen throughout the extended flowering period of the female cultivars. Using as a guide the number of viable pollen grains per 1-m branch, defined here as the calculated effective pollen productivity (EPP), we identified plants with an elevated EPP that flower concurrently with the female cultivars.


Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 290
Author(s):  
Abdul Kader Alabdullah ◽  
Graham Moore ◽  
Azahara C. Martín

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.


1972 ◽  
Vol 52 (4) ◽  
pp. 569-574 ◽  
Author(s):  
K. C. YEUNG ◽  
E. N. LARTER

A study of the pollen production properties of three hexaploid triticale strains (Triticale hexaploide Lart.) showed that their anther length was significantly greater than that of wheat anthers (Triticum aestivum L. em Thell.) and the estimated number of pollen grains per anther ranged from 15,000 to 21,000. In comparison, a total of 8000 grains per anther was estimated for wheat, cult Manitou. Eighty-nine percent anther extrusion occurred in triticale cult Rosner, while Manitou averaged 70% anther extrusion. The period of anthesis of triticale varied according to strain but generally was of longer duration than in Manitou and thereby promoted outcrossing. Using a triticale strain carrying a dominant marker gene, 50% seed-set was obtained at a distance of 12 m leeward of the pollen source; however, a small percentage was still obtained at a distance of 30 m. It would appear from the limited number of triticales used in this study that a wide range of variability exists within this species in its pollen production and disseminating properties. With appropriate selection pressures, strains with an outbreeding habit could be developed for the purpose of hybrid seed production.


2021 ◽  
Vol 7 (3) ◽  
pp. 64-69
Author(s):  
L. Bayramov

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.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yoon Kim ◽  
Sun-Ho Kim ◽  
Dong-Min Shin ◽  
Soo-Hwan Kim

ATBS1-INTERACTING FACTOR 2 (AIF2) is a non-DNA-binding basic-helix-loop-helix (bHLH) transcription factor. Here, we demonstrate that AIF2 negatively modulates brassinosteroid (BR)-induced, BRASSINAZOLE RESISTANT 1 (BZR1)-mediated pollen and seed formation. AIF2-overexpressing Arabidopsis plants (AIF2ox) showed defective pollen grains and seed production while two AIF2 knockout mutants, aif2-1 and aif2-1/aif4-1, displayed opposite phenotypes. Genes encoding BZR1-regulated positive factors of seed size determination (SHB1, IKU1, MINI3) were suppressed in AIF2ox and genes for negative factors (AP2 and ARF2) were enhanced. Surprisingly, BZR1-regulated pollen genes such as SPL, MS1, and TDF1 were aberrantly up-regulated in AIF2ox plants. This stage-independent abnormal expression may lead to a retarded and defective progression of microsporogenesis, producing abnormal tetrad microspores and pollen grains with less-effective pollen tube germination. Auxin plays important roles in proper development of flower and seeds: genes for auxin biosynthesis such as TCPs and YUCCAs as well as for positive auxin signalling such as ARFs were suppressed in AIF2ox flowers. Moreover, lipid biosynthesis- and sucrose transport-related genes were repressed, resulting in impaired starch accumulation. Contrarily, sucrose and BR repressed ectopic accumulation of AIF2, thereby increasing silique length and the number of seeds. Taken together, we propose that AIF2 is negatively involved in pollen development and seed formation, and that sucrose- and BR-induced repression of AIF2 positively promotes pollen production and seed formation in Arabidopsis.


Horticulturae ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 508
Author(s):  
Jie Qiu ◽  
Chao Gao ◽  
Hongli Wei ◽  
Biao Wang ◽  
Yang Hu ◽  
...  

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.


2011 ◽  
Vol 11 (3) ◽  
pp. 241-249 ◽  
Author(s):  
Carlos Eduardo da Silva Monteiro ◽  
Telma Nair Santana Pereira ◽  
Karina Pereira de Campos

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.


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