Abstract:
A field experiment was conducted at the research farm of Hunan Agricultural University, Hunan,
China in single rice season. Super high-yielding rice Liangyoupeijiu (LYPJ) was grown both in
transplanting and direct seeding conditions under conventional tillage (CT) and no-tillage (NT)
systems to determine the effects on photosynthetic characteristics. Differences in response of
photosynthetic characteristics to NT were found in transplanting and direct-seeding conditions.
For transplanting, the negative effects of NT on the photosynthetic capability came from the
decreasing ratio of chlorophyll a/b, the soluble protein contents per unit fresh weight and the
specific leaf weight (SLW) which were stronger than the positive effects of NT through the
increasing of the chlorophyll content per unit fresh weight at midtillering (MT), panicle initiation
(PI) and heading (HD) stages, which led to net photosynthetic rate per unit leaf area (PN) in NT
which was slightly lower than in CT at all of the three growth stages. For the direct seeding, the
negative effects of NT on the photosynthetic capability was found through the decreasing of the
chlorophyll contents, the soluble protein contents per unit fresh weight which were stronger than
the positive effects of NT through the increasing of the chlorophyll a/b ratio and the SLW at MT,
whereas the negative effects of NT on the photosynthetic capability came from the decreasing of
the chlorophyll contents, the soluble protein contents per unit fresh weight which were weaker
than the positive effects of NT came from the increasing of the SLW at PI and HD stages, which
caused PN in NT was slightly lower than that in CT at MT whereas it was slightly higher at PI
and HD stages. |
