Abstract
Various genes which control or affect heading time have been found in rice. Out of them, Se1 and E1 loci play important roles in determining heading time by controlling photosensitivity. An isogenic-line pair of late and early lines were developed from progenies of the F1 from Suweon 258 × 36U. A lateness gene tentatively designated as “Ex” was found to control the difference in heading time between the early and late lines mentioned above. The present study was conducted to examine the effect of Ex on yield and related traits. Indica-type variety Suweon 258 was crossed with 36U, which is an Ur1 (Undulate rachis-1) isogenic line of IR36. In the F2 population, comparatively early-heading, late-heading and intermediate-heading plants were segregated. Segregation similar to that by the three types of heading was observed in the F3 and later generations. A late-heading plant and an early-heading plant were selected in the F8 population from an intermediate-heading F7 plant, for developing L and E of the isogenic-line pair, respectively. Experiments for L and E were conducted by randomized block design with three replications. Transplanting was conducted on May 3 at a planting distance of 30 cm × 15 cm with two seedlings per hill to an experimental field of the Faculty of Agriculture, Kochi University. Chemical fertilizers containing N, P2O5 and K2O were applied at the nitrogen levels of 4 g/m2, 9 g/m2 and 18 g/m2 in total being denoted by "N4", "N9" and "N18", respectively. Yield, yield components and other traits were measured. Ex delayed 80%-heading by 17 or 18 days in L as compared with E. In total brown rice yield (g/m2), L was 635, 606 and 590, and E was 577, 548 and 501, respectively, at N18, N9 and N4, indicating that Ex increased this trait by 10% to 18%. Ex increased yield-1.5 mm sieve (g/m2) b 9% to 15% at the three fertilizer levels. Ex increased the spikelet number per panicle by 16% to 22%. As a result, the spikelet number per m2 was increased by 11% to 18% at the three fertilizer levels. Ex decreased 1000-grain weight (g) by 2 to 4%. L was not significantly different from E in ripened-grain percentage, fertilized-spikelet percentage and percentage of ripened grains to fertilized spikelets. Hence, it is inferred that Ex increased yield by increasing spikelet number per panicle. Hence, Ex could be utilized to develop high yielding varieties for warmer districts.
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Claims 9
Claim · model-written summary
Ex delayed heading by 17 or 18 days.
- Taxon
- rice
Oryza sativat0 - Material
- Le0
- Treatment
- Exe0
- Gene
- Exe0
- Outcome
- 80%-headinge0
- Direction
- delayede0
- Value
- 17 or 18 dayse0
- Comparator
- Ee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Ex delayed 80%-heading by 17 or 18 days in L as compared with E.”
t0“Indica Rice”
Claim · model-written summary
Ex increased brown rice yield by 10% to 18%.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Ex increased this trait by 10% to 18%.”
t0“Indica Rice”
Claim · model-written summary
Ex increased sieve yield by 9% to 15%.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Ex increased yield-1.5 mm sieve (g/m2) b 9% to 15% at the three fertilizer levels.”
t0“Indica Rice”
Claim · model-written summary
Ex increased spikelets per panicle by 16% to 22%.
- Taxon
- riceOryza sativat0
- Treatment
- Exe0
- Outcome
- spikelet number per paniclee0
- Direction
- increasede0
- Value
- 16% to 22%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Ex increased the spikelet number per panicle by 16% to 22%.”
t0“Indica Rice”
Claim · model-written summary
Ex increased spikelets per area by 11% to 18%.
- Taxon
- riceOryza sativat0
- Treatment
- Exe1
- Outcome
- spikelet number per m2e0
- Direction
- increasede0
- Value
- 11% to 18%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the spikelet number per m2 was increased by 11% to 18% at the three fertilizer levels.”
t0“Indica Rice”
e1“Ex increased the spikelet number per panicle by 16% to 22%.”
Claim · model-written summary
Ex decreased grain weight by 2 to 4%.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Ex decreased 1000-grain weight (g) by 2 to 4%.”
t0“Indica Rice”
Claim · model-written summary
L and E did not significantly differ in three ripening measures.
- Taxon
- riceOryza sativat0
- Material
- Le0
- Outcome
- ripened-grain percentage, fertilized-spikelet percentage and percentage of ripened grains to fertilized spikeletse0
- Direction
- not significantly differente0
- Comparator
- Ee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“L was not significantly different from E in ripened-grain percentage, fertilized-spikelet percentage and percentage of ripened grains to fertilized spikelets.”
t0“Indica Rice”
Claim · model-written summary
Ex increased yield by increasing spikelets per panicle.
- Taxon
- riceOryza sativat0
- Gene
- Exe0
- Outcome
- yielde0
- Direction
- increasede0
- Qualifier
- increasing spikelet number per paniclee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Ex increased yield by increasing spikelet number per panicle.”
t0“Indica Rice”
Claim · model-written summary
Ex could be used to develop higher yielding varieties for warmer districts.
- Taxon
- riceOryza sativat0
- Gene
- Exe0
- Outcome
- develop high yielding varietiese0
- Setting
- warmer districtse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Ex could be utilized to develop high yielding varieties for warmer districts.”
t0“Indica Rice”