Rice Seedlings Germinated in Water with Normal and Impeded Environmental Gas Exchange

Germination and seedling growth under anaerobic conditions in Echinochloa crus‐galli (barnyard grass)*

“…One of the most obvious effects of anaerobiosis on seedling growth in Eehinoehloa was on root emergence. Under anaerobic germination, no radical emergence was observed, as reported before in rice (Vartapetian, Andreeva & Nuritdina, 1978;Kordan, 1972).…”

Effects of submergence on development and gravitropism in the coleoptile of Oryza sativa L.

“…Whether submerged coleoptiles respond to gravistimulation while under water has yet to be tested. It is obvious that a lack of gravitropic responsiveness is no serious disadvantage for the coleoptiles since buoyancy determines their direction of growth (Kordan 1972(Kordan , 1974. Accordingly, submerged coleoptiles display vertical orientation though in a somewhat inaccurate form that Kordan (1972) described as circumnutational (Fig.…”

“…The dimorphism of rice coleoptiles under different germination conditions has been noted for some time (Kordan 1972(Kordan , 1974Hoson and Wada 1980;Rascio et al 1987). The modifications of the organ induced by submergence, which include anatomical as well as metabolic specialization for rapid growth, have to be considered as alterations under physiological conditions since rice naturally germinates and grows under water (Kordan 1972).…”

“…The modifications of the organ induced by submergence, which include anatomical as well as metabolic specialization for rapid growth, have to be considered as alterations under physiological conditions since rice naturally germinates and grows under water (Kordan 1972). Investigations with internodes of deep-water rice revealed a mobilization of reserve starch during submergence (Raskin and Kende 1984) and a lowered starch content in rice coleoptiles grown under anoxia was reported by Rascio et al (1987).…”

A Varietal Difference in Coleoptile Growth is Correlated with Seedling Establishment of Direct Seeded Rice in Submerged Field under Low-Temperature Conditions

“…There may exist three morphologically and physiologically distinctive growth stages from sowing to seedling establishment in submerged paddy fields; the 1st is the germination, the 2nd is the coleoptile elongation under low oxygen tension, and the 3rd is the elongation and appearance of the 1st leaf and radicle after enough oxygen being supplied through the coleoptile (Kordan, 1972;Kordan, 1974;Alpi and Beevers, 1983;Alpi et a!., 1985;Setter et a!., 1994). Although the relationship between seedling vigor and seedling length at certain days after sowing (Sasaki and Yamazaki, 1971;Ikehashi, 1973;Jones and Peterson, 1976;Li and Rutgar, 1980;Kotaka and Abe, 1988;Kowata et a!., 1992;Amana et a!., 1993;Redona and Mackill, 1996) and the relationship between seedling vigor and germination index (Kotaka and Abe, 1988;Kowata et al, 1992) have been studied, few physiological studies focusing on the above 3 distinctive growth stages under submerged conditions have been reported.…”