The in vitro Germination of Pollen of Setaria sphacelata 2. Relationships between Boron and Certain Cations

Abstract

The effects of different calcium levels upon germination and tube growth of the pollen of Setaria sphacelata (Schum.) Stapf and Hubbard were studied at low, optimal and high levels of boron. Calcium (10 and 100 mg/1) stimulated germination at all levels of boron and enhanced tube growth to an even greater degree. The inhibitory effects of high boron levels (50 mg/1) were largely overcome by addition of 10 to 100 mg/1 calcium. Magnesium (1 and 10 mg/1) stimulated germination and tube growth at optimal and high boron levels, but 100 mg/1 magnesium were highly inhibitory. Potassium and sodium had little effect upon pollen germination or tube growth at any level of boron supply. It was concluded that calcium, together with sucrose and borate, might be required for optimal germination and growth of the pollen tubes. Nevertheless, the tubes obtained were much shorter than required for fertilisation in vivo, indicating either that some essential factor was still missing or that the pollen is inherently incapable of producing tubes of adequate length.I wish to thank dr. Donald T. Krizek for critically reading the manuscript.

Studies on Cellular Site of Calcium Action in Promoting Pollen Growth

“…The findings Ihat Ca ions promote pollen fjei-miiialion and tube growth driimaticaily (3, 11, 15, 1(>), have led to fmlher investigations ol' tbe mode of Ca action at Ihe cellular level. Ca ions have also heen shown to induce the mutual stimulafion effect (3) and to protect pollen cells from various chemical and physical iiihibilors (11,15), when pollen was cuUured in vitro.…”

Estimation of Pollen Viability, Shedding Pattern, and Longevity of Creeping Bentgrass on Artificial Media

“…(Ahloowalla, 1973) and Kentucky bluegrass ( Poa pratensis L.; Teare et al, 1970), but not as yet with creeping bentgrass. Sucrose (Bair and Loomis, 1941; DeBruyn, 1966a, b), H 3 BO 3 (DeBruyn, 1966a, b), and Ca ions (Cook and Walden, 1967) are three of the most common nutrient components employed when formulating an artificial medium for in vitro pollen germination.…”