Agriculture Reference
In-Depth Information
7
CROP IMPROVEMENT
Rice is the major source of food for more than 2.7 billion
people and planted on nearly one-tenth of earth's arable land.
Of 130 million hectare of rice land 30% is subjected to salinity
problems, 20% drought and 10% low temperature at high
latitude and altitude areas were well documented in Japan
(Shimono et al. 2007), Korea, North East and southern China,
Bangladesh, India, Nepal and other countries (Lee 2001, Kaneda
and Beachell 1974). In similar low temperature conditions
severe yield loses were reported in Australia (Farrell et al. 2001),
Italy and United States (Board et al. 1980).
Cold acclimatization is a process which increases the cold
tolerance of the organism, after exposure to low, non freezing
temperatures. The acclimatization ensures that cold tolerant
species can endure harsh winter conditions, by preparing them
to sub-zero temperatures, cold sensitive plants such as rice
have limited abilities to cold climate and are therefore easily
damaged during winter time.
The development of more tolerant varieties by using
biotechnological methods is desirable, since the yields are
expected to improve due to a prolonged vegetative period.
