Pleiotropic Effect of GNP1 Underlying Grain Number per Panicle on Sink, Source and Flow in Rice
Rice yield potential is largely determined by the balance among source capacity, sink strength, and flow fluency. Our previous study indicated that the gene GNP1 encoding gibberellin biosynthesis gene GA20ox1 affects grain number per panicle (GNP) in rice, thus resulting in increase of grain yield....
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Published in | Frontiers in plant science Vol. 11; p. 933 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Frontiers Media S.A
19.06.2020
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Subjects | |
Online Access | Get full text |
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Summary: | Rice yield potential is largely determined by the balance among source capacity, sink strength, and flow fluency. Our previous study indicated that the gene
GNP1
encoding gibberellin biosynthesis gene
GA20ox1
affects grain number per panicle (GNP) in rice, thus resulting in increase of grain yield. To clarify
GNP1
effect on sink, source and flow in regulating rice grain yield, we compared Lemont, a
japonica
(
geng
) cultivar, with its near-isogenic line (NIL-
GNP1
TQ
) in Lemont background with introgression of the allele at
GNP1
from Teqing, a high-yielding
indica
(
xian
) cultivar. NIL-
GNP1
TQ
exhibited averagely 32.8% more GNP than Lemont with the compensation by reduced seed setting rate, panicle number and single-grain weight. However, NIL-
GNP1
TQ
still produced averagely 7.2% higher grain yield than Lemont in two years, mainly attributed to significantly more filled grain number per panicle, and greater vascular system contributing to photoassimilates transport to spikelets. The significantly decreased grain weight of superior spikelets (SS) in NIL-
GNP1
TQ
was ascribed to a significant decrease of grain size while the significantly decreased grain weight of inferior spikelets (IS) ascribed to both grain size and poor grain-filling as compared with Lemont. The low activities of key enzymes of carbon metabolism might account for the poor grain-filling in IS, which resulted in more unfilled grains or small grain bulk density in NIL-
GNP1
TQ
. In addition, low seed setting rate and grain weight of IS in NIL-
GNP1
TQ
might be partially resulted from significantly lower carbohydrate accumulation in culms and leaf sheath before heading compared with Lemont. Our results indicated that significantly increased GNP from introgression of
GNP1
TQ
into Lemont did not highly significantly improve grain yield of NIL-
GNP1
TQ
as expected, due primarily to significant low sink activities in IS and possible insufficient source supply which didn’t fully meet the increased sink capacity. The results provided useful information for improving rice yield potential through reasonably introgressing or pyramiding the favorable alleles underlying source-related or panicle number traits by marker-assisted selection. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Edited by: Hanwei Mei, Shanghai Agrobiological Gene Center, China These authors have contributed equally to this work Reviewed by: Longbiao Guo, China National Rice Research Institute, Chinese Academy of Agricultural Sciences, China; Conxita Royo, Institute of Agrifood Research and Technology (IRTA), Spain This article was submitted to Plant Breeding, a section of the journal Frontiers in Plant Science |
ISSN: | 1664-462X 1664-462X |
DOI: | 10.3389/fpls.2020.00933 |