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Dong M.-H.,Suzhou Academy of Agriculture science | Dong M.-H.,Yangzhou University | Gu J.-R.,Suzhou Academy of Agriculture science | Chen P.-F.,Suzhou Academy of Agriculture science | And 2 more authors.
Zhiwu Shengli Xuebao/Plant Physiology Journal | Year: 2013

To investigate the changes of abscisic acid (ABA) content in grains at different spikelet positions of rice and explore their relations with grain-filling rates, two super rice genotypes, 'Yangliangyou 6' (indica rice) and 'Wuyunjin 24' (japonica rice) were field-grown. The changes of ABA content in each group of spikelets at middle part on a panicle during grain filling were determined. Meanwhile, to test and verify the hypothesis that ABA is involved in mediating the postanthesis development of the different categories of spikelets, low concentration (75.7 μmol·L-1) of ABA was sprayed on the two genotypes at early grain-filling stage. The results showed that earlier-flowered spikelets exerted dominance over later-flowered ones in grain-filling rate and grain weight. There was no difference between the two genotypes. Later-flowered spikelets contained higher concentration of soluble sugars than the earlier-flowered ones at early grain-filling stage, indicating that carbohydrate supply may not be a limiting factor to the development of inferior spikelets. Similar to grainfilling rate, earlier-flowered spikelets contained a higher ABA content than later-flowered ones. The grain-filling rate was significantly and positively correlated with ABA content. Application of low concentration of ABA at early grain-filling stage significantly increased grain weight of those later-flowered grains on the proximal secondary branch and the same branch. The results indicate that low ABA content in inferior spikelets results in their poor grain filling, and a higher ABA content in rice spikelets is required to maintain a faster grain-filling rate. Above all, the results suggest that the promotion of ABA content in grains at earlier grain-filling stage could enhance the transformation efficiency of sucrose to starch, and eventually accelerate grain filling.

Wang X.-Z.,Yangzhou University | Wang X.-Z.,Service Center for Efficient | Wang A.-L.,Yangzhou University | Wang S.-H.,Lixiahe Region Agricultural Research Institute of Jiangsu | And 5 more authors.
Journal of Ecology and Rural Environment | Year: 2011

Influence on the properties of turf-bed and growth of creeping bentgrass based on cow-manure-vermicompost as the basic materials were studied to determine the feasibility and effectiveness of cow-manure-vermicompost as substrate modifier of the turf-bed. The results show that pH value of the turf-bed decreased with an increasing addition of vermicompost while conductivity(σ) value remarkably increased. Conductivity value in 100 g • kg-1 vermicompost treatment was about 16 times of that in CK. But after the turf establishment stage, conductivity values decreased to the level close to that of CK. Compared with addition of 40 g • kg-1 peat, the addition of 40, 60, 80 and 100 g • kg-1 vermicompost can significantly shorten the time of the formation process of the lawn, considerably increase the regeneration speed, and remarkably improve the chlorophyll content and the clipping content. The growth of grass in vermicompost treatments was better than that in peat treatment. During actual performance, it should be considered that the growth of grass may be too fast at the later stage due to the higher content of phosphorus in vermicompost.

Dong M.,Suzhou Academy of Agricultural Science | Dong M.,Yangzhou University | Gu J.,Suzhou Academy of Agricultural Science | Gu J.,Yangzhou University | And 7 more authors.
Journal of Proteomics | Year: 2014

The biological functions of the differentially abundant proteins between superior and inferior spikelet grains were investigated based on the isobaric tags for relative and absolute quantification to further clarify the mechanism of rice grain filling at the proteomic level, as well as the response of inferior spikelets to drought dress (-. 20. kPa or -. 40. kPa). Compared with superior spikelets, inferior ones had lower sink strength due to the lower sink activities (lower abundances of ADP-glucose pyrophosphorylase, granule-bound starch synthase, starch branching enzyme and pullulanase) and smaller sink sizes (lower abundances of structural proteins). The slower and later grain filling resulted from the weaker decomposition and conversion of photoassimilate and the slower cell division. Moderate drought stress (-. 20. kPa) promoted the grain filling of inferior spikelets through regulating the proteins associated with photoassimilate supply and conversion. These proteins may be important targets for rice breeding programs that raise the rice yield under drought condition. The findings offer new insights into rice grain-filling and provide theoretical evidences for better quality control and scientific improvement of super rice in practice. Biological significance: Rice cultivars with large panicles do not always guarantee high yield and grain quality probably due to the slow grain filling and many unfilled grains of inferior spikelets. In general, earlier-flowering superior spikelets, which are usually located on apical primary branches, fill faster and produce larger and heavier grains. In contrast, later-flowering inferior spikelets located on proximal secondary branches are either sterile or fill slowly and poorly, and the differences are more significant in large panicle rice or super rice. The increase of rice yield has been limited by the unsatisfactory grain filling of inferior spikelets, and the inferior spikelets are more prone to environmental factors during grain filling. Thus, we herein investigated the biological functions of differently abundant proteins between superior and inferior spikelet grains by using iTRAQ to unravel the mechanism of rice grain filling and the response of inferior spikelets to drought stress at proteomic level. This study offers new insights into rice grain-filling and provides valuable evidences for better quality control and scientific improvement of super rice in practice. © 2014 Elsevier B.V.

Xu J.,Yangzhou University | Wang B.,Lixiahe Region Agricultural Research Institute of Jiangsu | Wu Y.,Yangzhou University | Du P.,Yangzhou University | And 5 more authors.
Theoretical and Applied Genetics | Year: 2011

Photoperiod-thermo-sensitive genic male sterile (PTGMS) rice exhibits a number of desirable traits for hybrid rice production. The cloning genes responsible for PTGMS and those elucidating male sterility mechanisms and reversibility to fertility would be of great significance to provide a foundation to develop new male sterile lines. Guangzhan63S, a PTGMS line, is one of the most widely used indica two-line hybrid rice breeding systems in China. In this study, genetic analysis based on F2 and BC1F2 populations derived from a cross between Guangzhan63S and 1587, determined a single recessive gene controls male sterility in Guangzhan63S. Molecular marker techniques combined with bulked-segregant analysis (BSA) were used and located the target gene (named ptgms2-1) between two SSR markers RM12521 and RM12823. Fine mapping of the ptgms2-1 locus was conducted with 45 new Insertion-Deletion (InDel) markers developed between the RM12521 and RM12823 region, using 634 sterile individuals from F2 and BC1F2 populations. Ptgms2-1 was further mapped to a 50.4 kb DNA fragment between two InDel markers, S2-40 and S2-44, with genetic distances of 0.08 and 0.16 cM, respectively, which cosegregated with S2-43 located on the AP004039 BAC clone. Ten genes were identified in this region based on annotation results from the RiceGAAS system. A nuclear ribonuclease Z gene was identified as the candidate for the ptgms2-1 gene. This result will facilitate cloning the ptgms2-1 gene. The tightly linked markers for the ptgms2-1 gene locus will further provide a useful tool for marker-assisted selection of this gene in rice breeding programs. © Springer-Verlag 2010.

Xiao N.,Yangzhou University | Xiao N.,Lixiahe Region Agricultural Research Institute of Jiangsu | Sun G.,Saint Marys University, Halifax | Hong Y.,Yangzhou University | And 4 more authors.
Genetic Resources and Crop Evolution | Year: 2011

In the rice genome, insertions and eliminations of transposable elements have generated numerous transposon insertion polymorphisms (TIPs). Common wild rice (O. rufipogon Griff.), the ancestor of Asian cultivated rice (O. sativa L.), carries abundant genetic variations. To find subspecies-specific (SS) markers that can distinguish O. sativa ssp. indica and ssp. japonica, some long terminal repeat (LTR) sequences (sc1-14) of AA genome-specific RIRE retrotransposon were isolated from O. rufipogon genome. Sequences sc1 and sc12 were successfully utilized to develop the SS marker system based on retrotransposon inserted position polymorphisms. Twenty-two SS markers (ssi1-9, ssj1-13) were developed, where ssi1-9 are the indica-specific types, and ssj1-13 the japonica-specific types. The average accuracy of these markers in distinguishing the two subspecies is over 85%. SS marker ssj-10 can distinguish the two subspecies at 100% accuracy. Principal component analysis (PCA) showed that these markers could successfully distinguish indica from japonica varieties, regardless of their geographical origin. © 2011 Springer Science+Business Media B.V.

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