Premium
Germination Inhibition in Oryza Sativa and Control by Preplanting Soaking Treatments 1
Author(s) -
Mikkelsen D. S.,
Sinah M. N.
Publication year - 1961
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1961.0011183x000100050010x
Subject(s) - oryza sativa , biology , citation , germination , horticulture , library science , computer science , genetics , gene
D. S. Mikkelsen and M. N. Sinah THE seeds of many plant species, including Oryza saliva, often fail to germinate promptly after being exposed to favorable conditions. Instead, they may germinate at irregular intervals, with variable vigor. Delayed germination has been associated with a number of factors including impermeability of seeds or seed coats to water and gaseous diffusion, some special stimulus requirement, or the presence of inhibiting substances. It is commonly known that properly matured rice seed will attain a germination near 100% but that some varieties, especially long maturing Indica varieties, may exhibit dormancy. Often the period of dormancy will vary directly with the length of previous growing period. Removal of the hulls, botanically known as the lemma and palea, has been an effective method of breaking the dormancy of some varieties, according to Parija (6). It also generally allows faster germination of all rice seed. Hulled seed, however, is not desirable for field planting because it is extremely susceptible to disease. To date no effort has been made to determine the nature of the delayed germination in rough (unhulled) rice or to study the relation of preplanting soaking in various chemical solutions to reported faster germination, improved seedling growth, and occasional increased yields of rice. In 1958, Koves and Varga (5) reported that extracts of straw from several rice varieties contained substances capable of inhibiting the germination of Pap aver seeds. Similar extracts inhibited the elongation of Avena coleoptile sections. Svinarev and Borannikov (9) earlier reported that solutions in which rough rice had germinated inhibited the germination of other seed. They also observed that an organic substance excreted from rough rice seed reduced the germination of Echinochloa crusgalli. In unpublished work of Mikkelsen and Glazewski, six compounds have been extracted and identified in rice hull extracts and their physiological activities determined. The compounds identified as present in rice hull extracts are vanillic acid, ferulic acid, p-hydroxybenzoic acid, p-coumaric acid, p-hydroxybenzaldhyde, and indole acetic acid. Additional data concerning the nature of the inhibitors present in the hulls of