Effects of the application of a moderate alternate wetting and drying technique on the performance of different European varieties in Northern Italy rice system

Alternate wetting and drying (AWD) technique has been developed and evaluated on rice (Oryza sativa) systems in several countries worldwide for increasing water use efficiency and reducing negative effects of permanent flooding, like the increase in methane emissions and arsenic availability in soil. In this study, a paddy field experiment was carried out for two years to evaluate the application in Northern Italy rice area of a moderate AWD, i.e. only implemented during the vegetative phase of the crop and ponded water maintained thereafter, compared with Continuous Flooding (CF) system. The adaptability of 12 European commercial rice cultivars to AWD was investigated in terms of crop phenology, morphological traits, root production, nitrogen (N) uptake, yield, milled rice yield and microelement concentration in grains. Results showed substantial (40.7 %) water saving probably favoured by the presence of a shallow water table. In these pedoclimatic conditions, very limited effects of a mild AWD on crop status and final productivity were recorded and the commercial cultivars did not display significant different adaptabilities to the water stress. Moreover, AWD decreased arsenic (As) concentration in grain but increased grain Cadmium (Cd) being the degree of such a response dependent upon the variety, suggesting that the genotype plays an important role in this aspect of adaptation to AWD.info:eu-repo/semantics/acceptedVersio

Helicia cochinchinensis Lour.

原著和名: ヤマモガシ科名: ヤマモガシ科 = Proteaceae採集地: 鹿児島県 高隈山麓 (大隅 高隈山麓)採集日: 1965/10/29採集者: 萩庭丈壽整理番号: JH008969国立科学博物館整理番号: TNS-VS-95896

Genome-Wide Association Study for Traits Related to Plant and Grain Morphology, and Root Architecture in Temperate Rice Accessions

<div><p>Background</p><p>In this study we carried out a genome-wide association analysis for plant and grain morphology and root architecture in a unique panel of temperate rice accessions adapted to European pedo-climatic conditions. This is the first study to assess the association of selected phenotypic traits to specific genomic regions in the narrow genetic pool of temperate japonica. A set of 391 rice accessions were GBS-genotyped yielding—after data editing—57000 polymorphic and informative SNPS, among which 54% were in genic regions.</p><p>Results</p><p>In total, 42 significant genotype-phenotype associations were detected: 21 for plant morphology traits, 11 for grain quality traits, 10 for root architecture traits. The FDR of detected associations ranged from 3 · 10⁻⁷ to 0.92 (median: 0.25). In most cases, the significant detected associations co-localised with QTLs and candidate genes controlling the phenotypic variation of single or multiple traits. The most significant associations were those for flag leaf width on chromosome 4 (<i>FDR</i> = 3 · 10⁻⁷) and for plant height on chromosome 6 (<i>FDR</i> = 0.011).</p><p>Conclusions</p><p>We demonstrate the effectiveness and resolution of the developed platform for high-throughput phenotyping, genotyping and GWAS in detecting major QTLs for relevant traits in rice. We identified strong associations that may be used for selection in temperate irrigated rice breeding: e.g. associations for flag leaf width, plant height, root volume and length, grain length, grain width and their ratio. Our findings pave the way to successfully exploit the narrow genetic pool of European temperate rice and to pinpoint the most relevant genetic components contributing to the adaptability and high yield of this germplasm. The generated data could be of direct use in genomic-assisted breeding strategies.</p></div

Phenotypic correlations among plant morphology, grain quality and root traits.

<p>Phenotypic correlations among plant morphology, grain quality and root traits.</p

Stacked barplot for the ancestry of the available 391 rice accessions with K = 5.

<p>Stacked barplot for the ancestry of the available 391 rice accessions with K = 5.</p

Manhattan and Q-Q plots of GWAS results for grain quality traits.

<p>Manhattan and Q-Q plots of GWAS results for grain quality traits.</p

Manhattan and Q-Q plots of GWAS results for plant morphology traits.

<p>Manhattan and Q-Q plots of GWAS results for plant morphology traits.</p

Recorded traits.

<p>Recorded traits.</p

Manhattan and Q-Q plots of GWAS results for shoot and root dry weight.

<p>Manhattan and Q-Q plots of GWAS results for shoot and root dry weight.</p

Manhattan and Q-Q plots of GWAS results for root traits.

<p>Manhattan and Q-Q plots of GWAS results for root traits.</p