Kochia (Kochia scoparia) Pollen Dispersion, Viability and Germination

Abstract

Kochia pollen dispersion was measured during 24 and 48 h periods from a kochia population in an 8- by 10-m area in the center of a 1.6 ha fallow field. Pollen counts from traps at 50- and 100-cm heights declined rapidly with increasing distance from the pollen source. Pollen deposition was highest along the prevailing wind direction: up to 23 pollen grains cm–2were recovered 50 m from the pollen source along the southeast (SE) vector. Nonlinear regression analysis of pollen deposition along the SE vector was used to estimate that 99.9% of shed pollen would be deposited within 154.4 m of the source. Viability of pollen from greenhouse- and field-grown plants was measured using staining and germination assays. of four pollen stains tested, only 1,2,3-triphenyl tetrazolium chloride gave consistent results and did not stain heat-killed pollen. Depending on environmental conditions, kochia pollen remained viable from less than 1 d to 12 d. Length of kochia pollen viability was shortest under high temperatures (22 and 28 C) and low relative humidity (7 and 32%). Less than 0.5% germination was observed in 1.1% agar media with various additions; however, up to 17.8% germination was observed after incubation at 28 C in 100% relative humidity.

Effect of seasonality and time after anthesis on the viability and longevity ofCannabis sativapollen

“…The loss of viability, which is a continuous but arbitrary process, implies the need to determine the period of time when pollen grains are potentially viable. There are a number of contexts where it is important to test the functional quality of pollen: for example, genetics and pollen-stigma interaction, crop improvement and breeding programmes, gene bank maintenance, incompatibility and fertility studies, evaluation of pollen germinability after exposure to certain conditions, and evaluation of dispersal and gene flow (Stanley & Linskens 1974;Heslop-Harrison et al 1984;Dafni 1992;Shivanna & Rangaswamy 1992;Mulugeta et al 1994). Recent studies related to pollen viability have received great attention and are essential for the reproductive success, conservation and management of different plant species (Lyra et al 2011).…”

Effect of Moisture Content on Pollen Storage of Hevea Clone RRIM 600 and RRIT 251

“…Pollen staining tests by FCR (Fluorochromatic reaction) test and 1, 2, 3-TTC (Triphenyl tetrazolium chloride) are among the best and most widely used tests of pollen viability [7,8]. Both tests are principally the integrity of the vegetative cell plasma membrane and rely on the presence of a non-specific esterase in the pollen cytoplasm.…”

Evaluation of Viability, Shedding Pattern, and Longevity of Pollen from Genetically Modified (GM) Herbicide-tolerant and Wild-type Zoysiagrass (Zoysia japonica Steud.)

“…Staining with IKI and TTC are commonly used to estimate viability (Mulugeta et al 1994;Dafni and Firmage 2000). About 90% of the grains from both GM and non-GM zoysiagrass stained purple brown, and this coloring did not disappear.…”

“…For many species, this TTC method is helpful for estimating pollen viability (Mulugeta et al 1994;Huang et al 2004), whereas for others, it can yield false-positive scores for viability when compared with data from germination tests (Stone et al 1995;Wang et al 2004;Dafni et al 2005). Here, neither staining protocol proved appropriate for determining the pollen viability of Z. japonica.…”

“…Viability can be estimated by staining it with dyes such as iodine and potassium iodide (IKI) , triphenyl tetrazolium chloride (TTC) (Huang et al 2004), or fluoresceine diacetate (Eady et al 1995). However, these do not always apply coincidentally for many plant species (Mulugeta et al 1994). Therefore, pollen germination on an artificial medium has been established as a more faithful approach for evaluating viability in grass family members, including ryegrass (Ahloowalla 1973), Kentucky bluegrass (Teare et al 1970), maize (Geetha et al 2004), and creeping bentgrass (Fei and Nelson 2003).…”