POLLEN GERMINATION AND CHILLING SENSITIVITY IN TWO TOMATO CULTIVARS OF DIFFERING SENSITIVITY TO COOL NIGHT TEMPERATURE

1982 ◽  
Vol 62 (3) ◽  
pp. 765-770 ◽  
Author(s):  
N. P. A. HUNER ◽  
R. B. VAN HUYSTEE
Keyword(s):  
Low Temperature ◽  
Pollen Tube ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Differential Rate ◽  
Night Temperature ◽  
Pollen Grain Germination ◽  
Chilling Sensitivity ◽  
Tomato Cultivars ◽  
Cool Night

The effect of low night temperature on pollen tube formation and chilling sensitivity was compared in two tomato cultivars, Ontario 7515, free-setting at low temperature, and Ohio MR13, poor-setting at low temperature. The rate and extent of pollen grain germination in the Ontario 7515 cultivar far exceeded that of pollen grains obtained from the Ohio MR13 cultivar. In addition, the rate of pollen tube growth was greater in the free-setting cultivar than the poor-setting cultivar. No major differences were observed in the chilling sensitivity of the vegetative parts of these two tomato cultivars. It is concluded that the differential ability of these two tomato varieties to set fruit during growth at cool, night temperatures may be a function of differential flower production and a differential rate of pollen grain germination rather than a differential chilling sensitivity of the vegetative plant.

scholarly journals EXO70A2 is critical for the exocyst complex function in Arabidopsis pollen

2019 ◽  
Author(s):  
Vedrana Marković ◽  
Fatima Cvrčková ◽  
Martin Potocký ◽  
Přemysl Pejchar ◽  
Eva Kollárová ◽  
...  
Keyword(s):  
Pollen Tube ◽  
Membrane Trafficking ◽  
Complex Function ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Quiescent State ◽  
Pollen Grain Germination ◽  
Exocyst Complex ◽  
Developmental Switches ◽  
Arabidopsis Pollen

ABSTRACTPollen development, pollen grain germination and pollen tube elongation are crucial biological processes in angiosperm plants that need precise regulation to deliver sperm cells to fertilize ovules. Pollen grains undergo two major developmental switches: dehydration characterized by metabolic quiescent state, and rehydration upon pollination that leads to extraordinary metabolic and membrane trafficking activity, resulting in germination and rapid tip growth of pollen tubes. To sustain these processes, many plant housekeeping genes evolved their pollen-specific paralogs. Highly polarized secretion at a growing pollen tube tip requires the exocyst tethering complex responsible for specific targeting of secretory vesicles to the plasma membrane. Here, we describe that EXO70A2 (At5g52340) is the main exocyst EXO70 isoform in Arabidopsis pollen, which governs the conventional secretory function of the exocyst, analogically to EXO70A1 (At5g03540) in the sporophyte. Our analysis of a CRISPR-generated exo70a2 mutant revealed that EXO70A2 is essential for efficient pollen maturation, pollen grain germination and pollen tube growth. GFP:EXO70A2 was localized similarly to other exocyst subunits to the apical domain in growing pollen tube tips characterized by intensive exocytosis. Moreover, EXO70A2 could substitute for the EXO70A1 function in the sporophyte, indicating functional redundancy of these two closely related isoforms. Phylogenetic analysis revealed that the ancient duplication of EXO70A to two (or more) paralogs, one of which is highly expressed in pollen, occurred independently in monocots and dicots. In summary, EXO70A2 is a crucial component of the exocyst complex in the Arabidopsis pollen required for efficient plant sexual reproduction.

scholarly journals Pollen tube incompatibility reaction on the stigma in selfpollinated Sinapis alba L.

2014 ◽  
Vol 65 (1-2) ◽  
pp. 101-105 ◽  
Author(s):  
Renata Śnieżko ◽  
Krystyna Winiarczyk
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Pollen Grains ◽  
Pollen Tubes ◽  
Sinapis Alba ◽  
Pollen Grain ◽  
Tube Growth ◽  
Sinapis Alba L ◽  
Growth Changes ◽  
Incompatibility Reaction

After selfpollination of <em>Sinapis alba</em> L. pollen tubes growth is inhibited on the stigma. The pollen grains germinate 3-4 hours after pollination. The pollen give rise to one or more pollen tubes. They grow along the papillae. In the place of contact between the papilla and pollen tube the pellicula is digested. Then the direction of pollen tube growth changes completely. Pollen tubes grow back on the exine of their own pollen grain, or turn into the air. The pollen tubes growth was inhibited in 6-8 hours after selfpollination. After crosspollination usually there is no incompatibility reaction.

scholarly journals Pollen grain germination and fruit set in 'Brazilian seedless' sugar apple (Annona squamosa L.)

2012 ◽  
Vol 12 (4) ◽  
pp. 277-280 ◽  
Author(s):  
Hellenn Thallyta Alves Mendes ◽  
Márcia Regina Costa ◽  
Silvia Nietsche ◽  
João Alison Alves Oliveira ◽  
Marlon Cristian Toledo Pereira
Keyword(s):  
Fruit Set ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Pollen Grain Germination ◽  
Artificial Pollination ◽  
Randomized Design ◽  
Self Fertilization ◽  
Completely Randomized Design ◽  
Fruit Formation

The purpose of this study was to evaluate fruit set and pollen grain germination of 'Brazilian seedless' sugar apple. Two experiments were performed: 1) one in a completely randomized design with three treatments (natural and artificial pollination and self-fertilization), with three replications of 10 flowers per plot, 2) and the other in a completely randomized design with three treatments: pollen grains of a seeded wild-type, 'Brazilian seedless' and atemoya (hybrid of sugar apple and cherimoya) 'Gefner', with five replications. A fruit set of 100% was achieved by artificial pollination. No fruit formation was observed after self-fertilization. The percentage of pollen grain germination in vitro was highest for 'Brazilian seedless' (52.5%) and lowest for cultivar Gefner (5.9%). Preliminary results indicated that pollen grains of 'Brazilian seedless' are viable and that natural or artificial pollination is essential for fruit set.

scholarly journals In vitro germination and viability of pea pollen grains after application of organic nano-fertilizers

2017 ◽  
Vol 32 (1) ◽  
pp. 61-65 ◽  
Author(s):  
Natalia Georgieva ◽  
Ivelina Nikolova ◽  
Valentin Kosev ◽  
Yordanka Naydenova
Keyword(s):  
Pollen Tube ◽  
Pollen Germination ◽  
Culture Media ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Pollen Grain ◽  
In Vitro Germination ◽  
Pisum Sativum L ◽  
Pollen Tube Elongation

The objective of this study was to evaluate the influence of two organic nanofertilizers, Lithovit and Nagro, on in vitro germination, pollen tube elongation and pollen grain viability of Pisum sativum L cv. Pleven 4. The effect of their application was high and exceeded data for the untreated control (44.2 and 47.23 % regarding pollen germination and pollen tube elongation, respectively), as well as the effect of the control organic algal fertilizer Biofa (17.5 and 27.9 %, respectively). Pollen grains were inoculated in four culture media. A medium containing 15% sucrose and 1% agar had the most stimulating impact on pea pollen grains. Pollen viability, evaluated by staining with 1% carmine, was within limits of 74.72-87.97%. The highest viability of pollen grains was demonstrated after the application of Nagro organic nano-fertlizer.

scholarly journals Male gametophytic generation and a possible approach for selective pollination in carnation (Dianthus) breeding program

2011 ◽  
Vol 48 (No. 8) ◽  
pp. 368-375
Author(s):  
Tejaswini
Keyword(s):  
Grain Size ◽  
Pollen Tube ◽  
Dianthus Caryophyllus ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Breeding Program ◽  
Germination Capacity ◽  
Causal Organism ◽  
Pollen Tube Growth Rate ◽  
Pollen Grain Size

Present study focuses on making best possible use of male gametophytic generation in carnation breeding program. Exploration of pollen population revealed the existence of variability in terms of pollen morphology and histochemical content among as well as within varieties and species of Dianthus caryophyllus and D. chinensis sufficient to make selection. Pollen grain size and histochemical content were found to be associated with germination capacity and pollen tube growth rate. In addition, pollen germination capacity and elongation of pollen tube in response to presence of culture filtrate from F. oxysporum. f.sp. dianthi causal organism of fusarium wilt in carnation was found to be governed by pollen grain size and histochemical content of pollen grains. Entire result suggests the possibility of selecting the desired pollen grains from a&nbsp;pollen population and possibility of attempting selective pollination in carnation breeding program.

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