scholarly journals Labor, Seedling Establishment and Yield in Direct Seeding of Non-coated Rice Seeds Using a Puddling Seeder in the Cool Region of Japan

2016 ◽  
Vol 85 (2) ◽  
pp. 178-187
Author(s):  
Hiroyuki Shiratsuchi ◽  
Tadashi Andoh ◽  
Noriyuki Asanome ◽  
Akira Matsuda ◽  
Yoshiaki Kawana ◽  
...  
Keyword(s):  
Seedling Establishment ◽  
Direct Seeding ◽  
Rice Seeds ◽  
Cool Region

scholarly journals Dynamic genome-wide association analysis and identification of candidate genes involved in anaerobic germination tolerance in rice

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Ling Su ◽  
Jing Yang ◽  
Dandan Li ◽  
Ziai Peng ◽  
Aoyun Xia ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Genome Wide Association Study ◽  
Expression Profiles ◽  
Oxygen Deficiency ◽  
Direct Seeding ◽  
Genome Wide Association ◽  
Genome Wide ◽  
Anaerobic Germination ◽  
Dynamic Genome ◽  
Rice Seeds

Abstract Background In Asian rice production, an increasing number of countries now choose the direct seeding mode because of rising costs, labour shortages and water shortages. The ability of rice seeds to undergo anaerobic germination (AG) plays an important role in the success of direct seeding. Results In this study, we used 2,123,725 single nucleotide polymorphism (SNP) markers based on resequencing to conduct a dynamic genome-wide association study (GWAS) of coleoptile length (CL) and coleoptile diameter (CD) in 209 natural rice populations. A total of 26 SNP loci were detected in these two phenotypes, of which 5 overlapped with previously reported loci (S1_ 39674301, S6_ 20797781, S7_ 18722403, S8_ 9946213, S11_ 19165397), and two sites were detected repeatedly at different time points (S3_ 24689629 and S5_ 27918754). We suggest that these 7 loci (−log10 (P) value > 7.3271) are the key sites that affect AG tolerance. To screen the candidate genes more effectively, we sequenced the transcriptome of the flooding-tolerant variety R151 in six key stages, including anaerobic (AN) and the oxygen conversion point (AN-A), and obtained high-quality differential expression profiles. Four reliable candidate genes were identified: Os01g0911700 (OsVP1), Os05g0560900 (OsGA2ox8), Os05g0562200 (OsDi19–1) and Os06g0548200. Then qRT-PCR and LC-MS/ MS targeting metabolite detection technology were used to further verify that the up-regulated expression of these four candidate genes was closely related to AG. Conclusion The four novel candidate genes were associated with gibberellin (GA) and abscisic acid (ABA) regulation and cell wall metabolism under oxygen-deficiency conditions and promoted coleoptile elongation while avoiding adverse effects, allowing the coleoptile to obtain oxygen, escape the low-oxygen environment and germinate rapidly. The results of this study improve our understanding of the genetic basis of AG in rice seeds, which is conducive to the selection of flooding-tolerant varieties suitable for direct seeding.

Direct seeding of black spruce in northwestern Ontario: Seedbed relationships

1994 ◽  
Vol 70 (2) ◽  
pp. 151-158 ◽  
Author(s):  
R. L. Fleming ◽  
D. S. Mossa
Keyword(s):  
Seedling Establishment ◽  
Black Spruce ◽  
Mineral Soil ◽  
Soil Surface ◽  
Direct Seeding ◽  
First Year ◽  
Strongly Correlated ◽  
Seedling Mortality ◽  
Northwestern Ontario ◽  
Seedbed Preparation

A series of spot seeding experiments was set out on coarse-textured upland sites in northwestern Ontario to investigate how black spruce (Picea mariana [Mill.] B.S.P.) seedling establishment and growth could be improved by site selection and seedbed preparation. Virtually all germination occurred within the first growing season. Annual seedling mortality rates were greatest during the first year, then declined steadily and stabilized at low levels (<10%) after the third year. The highest fifth-year establishment ratios (seedlings/viable seed sown) were found on seedbeds derived from materials near the mineral soil/humus interface. On wetter sites (i.e., higher Soil Moisture Regimes) the best seedbeds occurred closer to the soil surface. Mean fifth year establishment ratios for the best seedbeds were 0.032 on moderately fresh to fresh sites, 0.146 on very fresh to moderately moist sites, and 0.082 on moist to very moist sites. On adjacent lowland sites, slow-growing, compact Sphagnum mosses had a mean establishment ratio of 0.179. Mean fifth-year seedling heights on upland sites ranged from 12 to 14 cm, and were not strongly correlated with site or seedbed type. Key words: direct seeding, black spruce, seedbed, seedling establishment, site type and germination

scholarly journals Mapping of QTLs controlling seedling establishment using a direct seeding method in rice

2010 ◽  
Vol 60 (4) ◽  
pp. 353-360 ◽  
Author(s):  
Natsuko Iwata ◽  
Hiroshi Shinada ◽  
Hitoshi Kiuchi ◽  
Takashi Sato ◽  
Kenji Fujino
Keyword(s):  
Seedling Establishment ◽  
Direct Seeding ◽  
Seeding Method

scholarly journals Dynamic genome-wide association analysis and identification of candidate genes involved in anaerobic germination tolerance in rice

2020 ◽  
Author(s):  
Ling Su ◽  
Jing Yang ◽  
Dandan Li ◽  
Ziai Peng ◽  
Aoyun Xia ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Genome Wide Association Study ◽  
Expression Profiles ◽  
Oxygen Deficiency ◽  
Direct Seeding ◽  
Genome Wide Association ◽  
Genome Wide ◽  
Anaerobic Germination ◽  
Dynamic Genome ◽  
Rice Seeds

Abstract Background: In Asian rice production, an increasing number of countries now choose the direct seeding mode because of rising costs, labour shortages and water shortages. The ability of rice seeds to undergo anaerobic germination (AG) plays an important role in the success of direct seeding.Results: In this study, we used 2,123,725 single nucleotide polymorphism (SNP) markers based on resequencing to conduct a dynamic genome-wide association study (GWAS) of coleoptile length (CL) and coleoptile diameter (CD) in 209 natural rice populations. A total of 26 SNP loci were detected in these two phenotypes, of which 5 overlapped with previously reported loci (S1_ 39674301, S6_ 20797781, S7_ 18722403, S8_ 9946213, S11_ 19165397), and two sites were detected repeatedly at different time points (S3_ 24689629 and S5_ 27918754). We suggest that these 7 loci (−log10 (P) value > 7.3271) are the key sites that affect AG tolerance. To screen the candidate genes more effectively, we sequenced the transcriptome of the flooding-tolerant variety R151 in six key stages, including anaerobic (AN) and the oxygen conversion point (AN-A), and obtained high-quality differential expression profiles. Four reliable candidate genes were identified: Os01g0911700 (OsVP1), Os05g0560900 (OsGA2ox8), Os05g0562200 (OsDi19-1) and Os06g0548200. Then qRT-PCR and LC-MS/ MS targeting metabolite detection technology were used to further verify that the up-regulated expression of these four candidate genes was closely related to AG.Conclusion: The four novel candidate genes were associated with gibberellin (GA) and abscisic acid (ABA) regulation and cell wall metabolism under oxygen-deficiency conditions and promoted coleoptile elongation while avoiding adverse effects, allowing the coleoptile to obtain oxygen, escape the low-oxygen environment and germinate rapidly. The results of this study improve our understanding of the genetic basis of AG in rice seeds, which is conducive to the selection of flooding-tolerant varieties suitable for direct seeding.

Elongation habit of mesocotyls and coleoptiles in weedy rice with high emergence ability in direct-seeding on dry paddy fields

2010 ◽  
Vol 61 (11) ◽  
pp. 911 ◽  
Author(s):  
Nam-Jin Chung
Keyword(s):  
Genetic Resources ◽  
Paddy Soil ◽  
Seedling Establishment ◽  
Large Scale ◽  
Soil Surface ◽  
Direct Seeding ◽  
Weedy Rice ◽  
Burial Depth ◽  
Sowing Depth ◽  
Rice Germplasm

Direct-seeding of rice on dry paddy soil could enable large-scale cultivation and cost-savings, but still has some problems including poor seedling establishment caused by low temperature and varied sowing depth. This research was performed to identify weedy rice genetic resources that may help to eliminate the problem of poor seedling establishment in direct-seeded rice on dry paddy soil in temperate regions. The genetic resources screened in this study were 128 genotypes consisting of 92 japonica weedy rices, 24 indica weedy rices, and 12 Korean bred cultivars. On average, weedy rice germplasm had superior abilities to emerge from greater depths than cultivated rices. Coleoptile and mesocotyl lengths were highly positively correlated with the emergence rate. Among the weedy rice germplasm, the japonica weedy rice WD-3 showed the highest level of emergence with the longest coleoptile and mesocotyl. The emergence ability of WD-3 was confirmed in both phytotron and field conditions. In the emerged plants in the field, the mesocotyl elongation increased with increasing burial depth in a logarithmic fashion, and coleoptile extension increased exponentially. The mesocotyl and coleoptile elongated to a length of seed burial depth, indicating that the mesocotyl and coleoptile of WD-3 could induce the safe development of the first leaf of the seedling at the soil surface. Therefore, the elongation habit of the mesocotyl and coleoptile of WD-3 could be one of the most important characteristics for the development of direct-seeding cultivars.

scholarly journals Osmotic treatment, growth regulator and rooter in Tabebuia roseoalba (RIDL.) Sandwith seeds for direct sowing

2020 ◽  
Vol 42 ◽  
Author(s):  
Alexandre Carneiro da Silva ◽  
Maiara Pilar Palmeira da Silva ◽  
Rayssa Zamith ◽  
Gustavo Galetti ◽  
Fatima Conceição Márquez Piña-Rodrigues
Keyword(s):  
Seedling Establishment ◽  
Forest Restoration ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Direct Seeding ◽  
Germination Test ◽  
Toxicity Effect ◽  
Induced Stress ◽  
Osmotic Treatment ◽  
Direct Sowing

Abstract: Direct seeding is a technology that reduces the costs of forest restoration projects and favors species which are difficult to establish for seedlings. The seeds osmotic treatment to accelerate and standardize germination and induce tolerance to environmental stresses may favor seedling establishment in field through direct sowing and contribute to the greater efficiency of this technique. With the purpose of favor seed germination and seedling establishment under direct seeding conditions in the field, Tabebuia roseoalba osmoprimed seeds in polyethylene glycol (PEG) solution and unconditioned seeds were treated with isolated and/or combined solutions of plant growth regulators (PGR) and rooting (RTG). These seeds were submitted to germination test and evaluated for percentage germination rate, germination speed index and normal seedlings, and to seedling emergence test by direct field seeding. RTG had a toxic effect on T. roseoalba seeds. Osmoconditioning induced stress tolerance by RTG during germination and on seedling establishment. PGR treatment favors seedling emergence in field conditions and alleviates the toxicity effect caused by RTG. These treatments have great potential for use in direct sowing of T. roseoalba seeds.

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