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Variation of
photosynthetic tolerance of rice cultivars (Oryza sativa
L.) to chilling temperature in the light
Xia Li*, Kun Cao, Chao
Wang, Zhi-wei Sun and Lina Yan
Institute
of Food Crops, Jiangsu High Quality Rice R and D Center,
Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu
Province, 210014, China.
*Corresponding author.
E -mail:
jspplx@jaas.ac.cn,
lixiahappy2008@gmail.com. Tel: 00862584390361. Fax: 00862584390322.
Accepted 18 September, 2009 |
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Forty-two
genotypes from the rice germplasm (Oryza sativa L.)
were identified under chilling temperature in the light at
bud, seedling and booting stages and divided into three
basic types; cultivars tolerant to chilling in the light
such as japonica, cultivars sensitive to chilling in
the light such as indica and cultivars that have
intermediate tolerance to chilling in the light such as
hybrid rice cultivar. Photosynthetic characteristics of two
cultivars tolerant (c.v. Taipei309 and Wuyujing3), two
cultivars sensitive (c.v.CA212 and Pusa) and two
intermediated tolerant (c.v. Liangyoupeijiu and Shanyou63)
to the chilling treatment in the
light were compared. The results showed that, compared to
the rice varieties chilling tolerant rice, the sensitive
ones indica exhibited a significant inhibition
of maximum photosynthetic rate (Pm) and a decrease in the
photochemical efficiency of photo-system 2 (PS2)( Fv/Fm),
which led to the accumulation of
AOS and decrease of Chl content. Interestingly, the
ratios of ASA/DHA and GSH/GSSG showed similar changes as
those with the performance of chilling tolerance, which
indicated that ASA/DHA cycle might be an important
protecting strategy in chilling tolerance, especially for
the middle tolerant ones. We describe a simple and effective
screening method and physiological basis for breeding crops
for enhanced tolerance to chilling temperature in the light.
Key
words:
Rice, chilling tolerance, photosynthetic rate, photo-system,
chilling stress, photooxidation,
gluthione, ascorbate. |
