Temperature affects the dormancy and germination of sympatric annual (Oryza meridionalis) and perennial (O. rufipogon) native Australian rices (Poaceae) and influences their emergence in introduced para grass (Urochloa mutica) swards

2015 ◽  
Vol 63 (8) ◽  
pp. 687 ◽  
Author(s):  
Sean M. Bellairs ◽  
Penelope A. S. Wurm ◽  
Beckie Kernich
Keyword(s):  
Soil Surface ◽  
Field Studies ◽  
Oryza Rufipogon ◽  
Oryza Species ◽  
Northern Australia ◽  
Seed Biology ◽  
Oryza Meridionalis ◽  
Native Grasslands ◽  
Wild Rice Species ◽  
Soil Temperatures

The seed biology of two ecologically and genetically important sympatric wild rice species from northern Australia was compared – perennial Oryza rufipogon Griff. and annual Oryza meridionalis N.Q.Ng. The aim was to determine mechanisms of dormancy exhibited at seed shed and to identify factors that trigger or inhibit germination. This information was used to investigate the ecology of in situ Oryza populations in introduced para grass swards (Urochloa mutica (Forssk.) T.Q. Nguyen) and to understand interactions between the two sympatric Oryza species. Primary dormancy in the two species is similar, namely, non-deep physiological dormancy, determined by external maternal structures and broken by warm temperature treatments equivalent to dry season soil temperatures. Light quality, smoke water, gibberellic acid and nitric acid treatments had minor influences on germination. Changes to the soil profile and aboveground biomass structure due to swards of U. mutica significantly affected emergence of O. meridionalis. Thus the influence of soil temperature explains the results of previous field studies in which biomass or litter on the soil surface prevented germination. This has implications for biodiversity management on monsoonal floodplains of northern Australia, where introduced pasture species produce greater biomass than native grasslands, reduce soil temperatures and are displacing native rices. There were differences between the Oryza species – dormancy was more quickly broken in annual O. meridionalis, reflecting the reduced need for investment in seed bank persistence for annual species in annually inundated and climatically reliable wetlands.

scholarly journals Evolutionary Analysis of GH3 Genes in Six Oryza Species/Subspecies and Their Expression under Salinity Stress in Oryza sativa ssp. japonica

Plants ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 30 ◽  
Author(s):  
Weilong Kong ◽  
Hua Zhong ◽  
Xiaoxiao Deng ◽  
Mayank Gautam ◽  
Ziyun Gong ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Gene Family ◽  
Salinity Stress ◽  
Common Ancestor ◽  
Oryza Rufipogon ◽  
Oryza Species ◽  
Evolutionary Analysis ◽  
Wild Rice Species ◽  
Oryza Punctata ◽  
Duplication Events

Glycoside Hydrolase 3 (GH3), a member of the Auxin-responsive gene family, is involved in plant growth, the plant developmental process, and various stress responses. The GH3 gene family has been well-studied in Arabidopsis thaliana and Zea mays. However, the evolution of the GH3 gene family in Oryza species remains unknown and the function of the GH3 gene family in Oryza sativa is not well-documented. Here, a systematic analysis was performed in six Oryza species/subspecies, including four wild rice species and two cultivated rice subspecies. A total of 13, 13, 13, 13, 12, and 12 members were identified in O. sativa ssp. japonica, O. sativa ssp. indica, Oryza rufipogon, Oryza nivara, Oryza punctata, and Oryza glumaepatula, respectively. Gene duplication events, structural features, conserved motifs, a phylogenetic analysis, chromosome locations, and Ka/Ks ratios of this important family were found to be strictly conservative across these six Oryza species/subspecies, suggesting that the expansion of the GH3 gene family in Oryza species might be attributed to duplication events, and this expansion could occur in the common ancestor of Oryza species, even in common ancestor of rice tribe (Oryzeae) (23.07~31.01 Mya). The RNA-seq results of different tissues displayed that OsGH3 genes had significantly different expression profiles. Remarkably, the qRT-PCR result after NaCl treatment indicated that the majority of OsGH3 genes play important roles in salinity stress, especially OsGH3-2 and OsGH3-8. This study provides important insights into the evolution of the GH3 gene family in Oryza species and will assist with further investigation of OsGH3 genes’ functions under salinity stress.

The occurrence of bacterial leaf blight in wild and cultivated rice in northern Australia

1973 ◽  
Vol 24 (2) ◽  
pp. 219 ◽  
Author(s):  
SJ Aldrick ◽  
IW Buddenhagen ◽  
APK Reddy
Keyword(s):  
Distinct Pattern ◽  
Leaf Blight ◽  
Oryza Rufipogon ◽  
Xanthomonas Oryzae ◽  
Bacterial Leaf Blight ◽  
Northern Australia ◽  
Asian Countries ◽  
Cultivated Rice ◽  
Wild Rice Species ◽  
First Time

Bacterial leaf blight (Xanthomonas oryzae) of rice is reported for the first time in Australia, where it occurred on cultivated rice and also on the indigenous wild rice species Oryza rufipogon and O. australiensis in the Northern Territory. The pathogen was isolated, characterized, and tested in Hawaii on a differential set of rice cultivars. All Australian isolates of X. oryzae had a lower average virulence, and a distinct pattern of virulence, in comparison with about 200 isolates from 10 Asian countries. The Australian isolates may represent a separate pathotype of X. oryzae, which suggests that the pathogen is indigenous and not recently introduced into northern Australia.

scholarly journals Willows Used for Phytoremediation Increased Organic Contaminant Concentrations in Soil Surface

2021 ◽  
Vol 11 (7) ◽  
pp. 2979
Author(s):  
Maxime Fortin Faubert ◽  
Dominic Desjardins ◽  
Mohamed Hijri ◽  
Michel Labrecque
Keyword(s):  
Soil Surface ◽  
Field Work ◽  
Field Studies ◽  
Soil Hydrology ◽  
Intensive Culture ◽  
Shrub Species ◽  
Short Rotation ◽  
Pollutant Concentrations ◽  
Polycyclic Aromatic ◽  
Made In

The Salix genus includes shrub species that are widely used in phytoremediation and various other phytotechnologies due to their advantageous characteristics, such as a high evapotranspiration (ET) rate, in particular when cultivated in short rotation intensive culture (SRIC). Observations made in past field studies suggest that ET and its impact on soil hydrology can also lead to increases in soil pollutant concentrations near shrubs. To investigate this, sections of a mature willow plantation (seven years old) were cut to eliminate transpiration (Cut treatment). Soil concentrations of polychlorinated biphenyls (PCBs), aliphatic compounds C10–C50, polycyclic aromatic hydrocarbons (PAHs) and five trace elements (Cd, Cr, Cu, Ni and Zn) were compared between the Cut and the uncut plots (Salix miyabeana ‘SX61’). Over 24 months, the results clearly show that removal of the willow shrubs limited the contaminants’ increase in the soil surface, as observed for C10–C50 and of 10 PAHs under the Salix treatment. This finding strongly reinforces a hypothesis that SRIC of willows may facilitate the migration of contaminants towards their roots, thus increasing their concentration in the surrounding soil. Such a “pumping effect” in a high-density willow crop is a prominent characteristic specific to field studies that can lead to counterintuitive results. Although apparent increases of contaminant concentrations contradict the purification benefits usually pursued in phytoremediation, the possibility of active phytoextraction and rhizodegradation is not excluded. Moreover, increases of pollutant concentrations under shrubs following migration suggest that decreases would consequently occur at the source points. Some reflections on interpreting field work results are provided.

scholarly journals Crop residues on short-term CO2 emissions in sugarcane production areas

2013 ◽  
Vol 33 (4) ◽  
pp. 699-708 ◽  
Author(s):  
Mariana M. Corradi ◽  
Alan R. Panosso ◽  
Marcílio V. Martins Filho ◽  
Newton La Scala Junior
Keyword(s):  
Co2 Emissions ◽  
Field Experiments ◽  
Crop Residues ◽  
Soil Surface ◽  
Dry Mass ◽  
Agricultural Crop ◽  
Short Term ◽  
Sugarcane Production ◽  
Soil Temperatures ◽  
Production Areas

The proper management of agricultural crop residues could produce benefits in a warmer, more drought-prone world. Field experiments were conducted in sugarcane production areas in the Southern Brazil to assess the influence of crop residues on the soil surface in short-term CO2 emissions. The study was carried out over a period of 50 days after establishing 6 plots with and without crop residues applied to the soil surface. The effects of sugarcane residues on CO2 emissions were immediate; the emissions from residue-covered plots with equivalent densities of 3 (D50) and 6 (D100) t ha-1 (dry mass) were less than those from non-covered plots (D0). Additionally, the covered fields had lower soil temperatures and higher soil moisture for most of the studied days, especially during the periods of drought. Total emissions were as high as 553.62 ± 47.20 g CO2 m-2, and as low as 384.69 ± 31.69 g CO2 m-2 in non-covered (D0) and covered plot with an equivalent density of 3 t ha-1 (D50), respectively. Our results indicate a significant reduction in CO2 emissions, indicating conservation of soil carbon over the short-term period following the application of sugarcane residues to the soil surface.

scholarly journals Seasonal emergence of selected summer annual weed species in dependence on soil temperature

2010 ◽  
Vol 56 (No. 9) ◽  
pp. 444-450 ◽  
Author(s):  
M. Jursík ◽  
J. Holec ◽  
J. Soukup ◽  
V. Venclová
Keyword(s):  
Chenopodium Album ◽  
Soil Surface ◽  
Main Field ◽  
Weed Species ◽  
Soil Temperatures ◽  
Field Emergence ◽  
The Relationship ◽  
Galinsoga Ciliata ◽  
Surface Layer Temperature ◽  
Mass Field

This study aimed to describe emergence cycles of selected weed species under Central European conditions in relation to cumulative soil temperatures from the start of the vegetation season. Emergence of Chenopodium album, Echinochloa crus-galli, Galinsoga ciliata, and Abutilon theophrasti was observed from March to October during the period 2001–2006 at two locations. The beginning of main field emergence was determined as the day when the sum of effective hour temperatures was achieved, and was detected from the second decade of April to early May for C. album, in the second decade of May for E. crus-galli, from late April to the beginning of May for G. ciliata, and from the end of April to mid-May for A. theophrasti. The relationship between cumulative soil surface layer temperature and weed mass field emergence at the beginning of the growing season is very direct (differences ±7 days) – but only when soil moisture is sufficient. In a drier spring, the beginning of mass field emergence occurs with 1–4 weeks of delay and field emergence is usually slower and protracted.

scholarly journals Keragaan Sifat Tahan Penyakit Blas dan Agronomi Populasi Silang Balik dan Haploid Ganda Turunan IR64 dan Oryza rufipogon

2016 ◽  
Vol 16 (2) ◽  
pp. 90
Author(s):  
Dwinita W. Utami ◽  
A. Dinar Ambarwati ◽  
Aniversari Apriana ◽  
Atmitri Sisharmini ◽  
Ida Hanarida ◽  
...  
Keyword(s):  
Double Haploid ◽  
Blast Resistance ◽  
Oryza Rufipogon ◽  
Screening Tests ◽  
Recurrent Parent ◽  
Wild Rice Species ◽  
Backcross Populations ◽  
Haploid Population ◽  
The One ◽  
Resistance Performance

<p>Blast Resistance Performance of Promising Lines Derived from Backcross and Double Haploid Population Between IR64 and Oryza rufipogon. Developing blast resistance varieties with superior agronomical performance has been the one of the important priorities in rice breeding program. Based on the purpose of this study the double haploid and backcross populations were developed using the most popular cultivar IR64 as recurrent parent and wild rice species Oryza rufipogon (Acc. IRGC 105491) as blast resistance donor parent. This study was initiated to analyze the blast resistance and agronomical performance of double haploid populations (DH_I, DH_II and DH_III) and backcross populations (BC2, BC3, and BC5), based on the green house and field screening tests. The results of statistical analysis showed that the blast resistance performance of DH population were diverse among DH_I, DH_II and DH_III. The smallest diversity was on the DH_III population. The same results were also detected on BC populations. The smallest diversity was on BC5 population. The diversity comparison between DH and BC population showed that DH_III population had smaller variation than BC5. Indicated that DH_III population has the most fixed population. The agronomic performance evaluation of DH_III population selected lines showed that Bio1, Bio2, and Bio8 qualitified as the candidate of promising lines.</p><p> </p><p><strong>Abstrak</strong></p><p>Perakitan varietas tahan blas sebagai galur harapan, merupakan salah satu prioritas dalam program pemuliaan padi. Dalam rangka mendukung program tersebut, telah dilakukan pembentukan populasi haploid ganda (HG) dan silang balik (BC) dengan IR64 sebagai tetua berulang dan Oryza rufipogon (No. aksesi IRGC 105491) sebagai tetua donor gen tahan penyakit blas. Penelitian ini bertujuan menganalisis keragaan tingkat ketahanan galur-galur haploid ganda (HG_I, HG_II, dan HG_III) dan galur-galur silang balik (BC2, BC3, dan BC5) terhadap penyakit blas di rumah kaca dan lapang, sehingga diperoleh kandidat galur harapan. Hasil pengujian beberapa populasi HG dan BC menunjukan bahwa terdapat variasi keragaan yang berbeda-beda. Variasi paling kecil terdapat pada populasi HG_III. Hasil yang sama juga diperoleh pada populasi silang balik (BC2-BC5). Variasi paling kecil terdapat pada populasi BC5. Bila dibandingkan antar populasi HG dan BC, tingkat variasi pada populasi HG_III lebih kecil dibandingkan dengan tingkat variasi pada populasi BC5. Hal ini menunjukkan bahwa tingkat homosigositas paling tinggi terdapat pada populasi HG_III. Berdasarkan evaluasi penampilan agronomis beberapa galur HG_III terpilih, diperoleh tiga galur kandidat galur harapan Bio1, Bio2, dan Bio8.</p>

Laboratory and field studies on the degradation of fipronil in a soil

Soil Research ◽  
2002 ◽  
Vol 40 (7) ◽  
pp. 1095 ◽  
Author(s):  
Guang-Guo Ying ◽  
Rai Kookana
Keyword(s):  
Soil Moisture ◽  
Half Life ◽  
Soil Moisture Content ◽  
Soil Surface ◽  
Field Studies ◽  
Transformation Product ◽  
Laboratory Studies ◽  
The Third ◽  
High Soil Moisture ◽  
Sulfone Derivatives

Degradation of a new insecticide/termiticide, fipronil, in a soil was studied in the laboratory and field. Three metabolites of fipronil (desulfinyl, sulfide, and sulfone derivatives) were identified from soils after treatment. Laboratory studies showed that soil moisture content had a great effect on the degradation rate of fipronil and products formed. High soil moisture contents (>50%) favored the formation of a sulfide derivative of fipronil by reduction, whereas low soil moisture (<50%) and well-aerated conditions favored the formation of fipronil sulfone by oxidation. Microorganisms in soil accelerated the degradation of fipronil to sulfide and sulfone derivatives. The third transformation product, a desulfinyl derivative, was formed by photodecomposition of fipronil in water and on the soil surface under sunlight. The desulfinyl derivative degraded rapidly in field soils with a half-life of 41–55 days compared with an average half-life of 132 days for fipronil. The half-life of the 'total toxic component' (fipronil and its metabolites) in field soil was 188 days on average.

Ethylene: A Witchweed Seed Germination Stimulant

Weed Science ◽  
1975 ◽  
Vol 23 (5) ◽  
pp. 433-436 ◽  
Author(s):  
Robert E. Eplee
Keyword(s):  
United States ◽  
Seed Germination ◽  
Clay Soil ◽  
Soil Surface ◽  
Field Studies ◽  
The United States ◽  
Major Contributor ◽  
Single Treatment ◽  
Striga Asiatica ◽  
Heavy Clay

Ethylene gas (C2H4) was found to stimulate the germination of witchweed [Striga asiatica(L.) O. Kuntze] seeds. Ethylene diffuses greater than 120 cm horizontally from point of injection and more than 90 cm below the soil surface. Rates of 0.42 kg/ha induced germination of witchweed seeds in sandy soil; but 1.1 kg/ha is required on a heavy clay soil. Witchweed seeds respond to ethylene after a period of preconditioning that is necessary to break dormancy. Under field conditions in the Carolinas, maximum response of seeds to ethylene occurs between late April and late July. Field studies indicate a 90% reduction in viable witchweed seeds occurs where a single treatment with ethylene has been applied. The use of ethylene appears now to be a major contributor toward the eventual eradication of witchweed from the United States.

scholarly journals Seed morphology and allelopathy of invasive Praxelis clematidea

2020 ◽  
Vol 48 (1) ◽  
pp. 261-272
Author(s):  
Suphannika INTANON ◽  
Buntoon WIENGMOON ◽  
Carol A. MALLORY-SMITH
Keyword(s):  
Invasive Species ◽  
Management Strategies ◽  
Soil Surface ◽  
Seed Morphology ◽  
Basic Knowledge ◽  
Agricultural Systems ◽  
Bidens Pilosa ◽  
Rubber Plantations ◽  
Plant Parts ◽  
Seed Biology

Praxelis [Praxelis clematidea (Griseb.) R.M.King & H.Rob.] is an invasive species that infests many agricultural systems globally, such as orchards, rubber plantations, and other economic crops. The purpose of this research was to study seed morphology, germination factors, and allelopathy of aboveground parts of P. clematidea. P. clematidea seeds are small, light, and possess pappi that allow them to be dispersed easily by wind or animals. Among four P. clematidea populations collected from different provinces in Thailand, the size of P. clematidea seeds ranged from 2.6 to 3.2 mm in length, 0.6 to 0.7 mm in width, and were 0.4 mm in thickness. The weight of P. clematidea seeds ranged from 0.13 to 0.21 mg. P. clematidea had about 44 to 48 seeds per head. Seeds germinated over a temperature range of 20 to 30 °C while high (45 °C) and low (10 °C) temperatures reduced germination. Maximum germination occurred when seeds were planted on the soil surface. No seedlings germinated when seeds were planted at a depth more than 1 cm. P. clematidea extracts from aerial plant parts at concentrations of 25 and 50% inhibited seedling growth of hairy beggarticks (Bidens pilosa L.). Basic knowledge of the seed biology of P. clematidea and allelochemicals can help in understanding the invasiveness and in developing management strategies for this weed.

Effect of pH, Nitrogen, and Tillage on Weed Control and Corn (Zea mays) Yield

Weed Science ◽  
1980 ◽  
Vol 28 (6) ◽  
pp. 719-722 ◽  
Author(s):  
J. J. Kells ◽  
R. L. Blevins ◽  
C. E. Rieck ◽  
W. M. Muir
Keyword(s):  
Zea Mays ◽  
Weed Control ◽  
Soil Ph ◽  
Soil Surface ◽  
Field Studies ◽  
Conventional Tillage ◽  
Corn Yield ◽  
No Tillage ◽  
Linear Effect ◽  
Surface Soil Ph

Field studies were conducted to determine the effect of soil surface (upper 5 cm) pH and tillage on weed control and corn (Zea maysL.) yield using simazine [2-chloro-4,6-bis-(ethylamino)-s-triazine] as the herbicide for weed control. Soil pH, weed control, and corn yield were examined under no-tillage and conventional tillage systems with and without added lime and different rates of nitrogen. Increased soil pH significantly increased weed control as compared with added lime vs. no added lime, where the surface soil pH influenced the effectiveness of the applied simazine. Soil pH had a greater effect on weed control under no-tillage than under conventional tillage. Conventional tillage significantly (P<.01) increased weed control, yield, and soil pH over no-tillage. Additions of lime as compared to unlimed treatments resulted in significantly increased weed control (83% vs. 63%), yield (5,930 vs. 5,290 kg/ha) and soil pH (5.91 vs. 5.22). The poorest weed control was observed with no-tillage on unlimed plots. A significant tillage by linear effect of nitrogen interaction for all variables resulted from a greater decrease (P<.01) in weed control and soil pH and a greater increase in yield with increased nitrogen under no-tillage than with conventional tillage.

Sign in / Sign up

Export Citation Format

Share Document