Weedy Rice Diversity in Southern Brazil

Weed Science ◽  
2021 ◽  
pp. 1-37
Author(s):  
Leonard Bonilla Piveta ◽  
José Alberto Noldin ◽  
Nilda Roma-Burgos ◽  
Vívian Ebeling Viana ◽  
Lariza Benedetti ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Flowering Time ◽  
Weed Management ◽  
Phenotypic Diversity ◽  
Weedy Rice ◽  
Phenotypic Traits ◽  
Southern Brazil ◽  
Variable Response ◽  
Cultivated Rice ◽  
Flowering Synchrony

Abstract Weedy rice (Oryza sativa L.) is one of the most troublesome weeds affecting rice (Oryza sativa L.) production in many countries. Weedy rice control is difficult in rice fields because the weed and crop are phenotypically and morphologically similar. Weedy rice can be a source of genetic diversity to cultivated rice. Thus, this study aimed to characterize the morphological diversity of weedy rice in Southern Brazil. Qualitative and quantitative traits of 249 accessions from eight rice growing mesoregions in Rio Grande do Sul (RS) and Santa Catarina (SC) states were analyzed. For each accession, 24 morphological descriptors (14 qualitative and 10 quantitative) were evaluated. All the 249 accessions from RS and SC are of indica lineage. Considering all the phenotypic traits evaluated, the accessions separated into 14 distinct groups. One of the largest groups consisted of plants that were predominantly tall and with green leaves, intermediate shattering, and variable in flowering time. Distinct subgroups exist within larger clusters, showing discernable phenotypic diversity within the main clusters. The variability in flowering time was high (77 to 110 d after emergence), indicating high potential for flowering synchrony with rice cultivars and, consequently, gene flow. This indicates the need to remove escapes when planting herbicide-resistant rice. Thus, weedy rice populations in Southern Brazil are highly diverse and this diversity could result in variable response to weed management.

Phenotypic diversity of weedy rice (Oryza sativa f. spontanea) biotypes found in California and implications for management

Weed Science ◽  
2020 ◽  
Vol 68 (5) ◽  
pp. 485-495
Author(s):  
Elizabeth Karn ◽  
Teresa De Leon ◽  
Luis Espino ◽  
Kassim Al-Khatib ◽  
Whitney Brim-DeForest
Keyword(s):  
Oryza Sativa ◽  
Chlorophyll Content ◽  
Plant Height ◽  
Wild Rice ◽  
Early Growth ◽  
Weedy Rice ◽  
Phenotypic Traits ◽  
Growth Stages ◽  
Cultivated Rice ◽  
Leaf Pubescence

AbstractWeedy rice (Oryza sativa f. spontanea Rosh.) is an emerging weed of California rice (Oryza sativa L.) that has potential to cause large yield losses. Early detection of weedy rice in the field is ideal to effectively control and prevent the spread of this weed. However, it is difficult to differentiate weedy rice from cultivated rice during early growth stages due to the close genetic and phenotypic relatedness of cultivated rice and weedy rice. The objective of this study is to examine phenotypic variation in weedy rice biotypes from California and to identify traits that could be used to visually identify weedy rice infestations at early growth stages for effective management. Greenhouse experiments were conducted in 2017 and 2018 using five phenotypically distinct biotypes of weedy rice found in California, along with diverse cultivated, weedy, and wild rice types in a randomized complete block design. We measured variation for 13 phenotypic traits associated with weedy rice and conducted principal component analysis and factor analysis to identify important weedy traits. Most weedy rice individuals within a biotype clustered together by phenotypic similarity. Pericarp color, hull color, chlorophyll content, grain length, plant height, leaf pubescence, collar color, and leaf sheath color account for most of the observed variation. California weedy rice biotypes are phenotypically distinct from wild rice and from weedy rice from the southern United States in their combinations of seed phenotypes and vegetative characteristics. In comparison with the locally grown temperate japonica cultivars, California weedy rice tends to be taller, with lower chlorophyll content and a red pericarp. Weedy rice biotypes vary in seed shattering and seed dormancy. For weedy rice management, plant height and chlorophyll content are distinct traits that could be used to differentiate weedy rice from the majority of cultivated rice varieties in California during vegetative stages of rice growth.

Characterization of the phenotypic variability in Colombian weedy rice (Oryza spp.)

Weed Science ◽  
2019 ◽  
Vol 67 (4) ◽  
pp. 441-452 ◽  
Author(s):  
Veronica Hoyos ◽  
Guido Plaza ◽  
Ana L. Caicedo
Keyword(s):  
Management Practices ◽  
Phenotypic Diversity ◽  
Phenotypic Variability ◽  
Morphological Diversity ◽  
Morphological Characters ◽  
Rice Production ◽  
Weedy Rice ◽  
Phenotypic Traits ◽  
Cultivated Rice ◽  
Production Areas

AbstractWeedy rice (Oryza spp.) is considered one of the main weeds in cultivated rice (Oryza sativa L.) around the world, having a great impact on both yield and quality of crop rice. Recent studies have characterized the range of morphological and genetic diversity in weedy rice from different locations and have revealed that there is often great morphological diversity within growing regions. No systematic attempt to characterize phenotypic diversity of weedy rice in Colombia, where this group of weeds greatly affects rice production, has yet been carried out. This study seeks (1) to establish the range of variation in various morphological characters for weedy rice collected in the five production zones of Colombia and to compare these with commercial varieties and landraces sown in the country, (2) to determine the association between weedy rice morphotypes and rice production areas in the country, and (3) to assess whether any association exists between morphology and recently discovered genetic groupings for weedy rice in Colombia. Based on a sampling of rice production areas in Colombia and evaluation of 27 phenotypic traits, a two-step cluster analysis identified four morphological groups for weedy rice in Colombia. These groupings had some limited association with geography and the genetic ancestries of weedy rice. Clustering showed that awn and apiculus color and awn length and presence are the most important predictors in defining morphological groupings. Understanding and classifying the morphological diversity may be helpful in understanding weedy rice origins, evolution, and potential management practices.

Surveys of Weed Management on Flooded Rice Yields in Southern Brazil

Weed Science ◽  
2021 ◽  
pp. 1-26
Author(s):  
Anelise L. Silva ◽  
Nereu A. Streck ◽  
Alencar J. Zanon ◽  
Giovana G. Ribas ◽  
Bruno L. Fruet ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Weed Control ◽  
Weed Management ◽  
Management Practices ◽  
Limiting Factors ◽  
Weedy Rice ◽  
Southern Brazil ◽  
Average Yield ◽  
Flooded Rice ◽  
Rice Yields

Abstract One of the main limiting factors for high yields of flooded rice (Oryza sativa L.) is the presence of weeds, especially herbicide-resistant weeds. The aim of this study was to evaluate the association of weed management practices adopted by flooded rice farmers in the State of Rio Grande do Sul (RS) to grain yield. For this purpose, 324 interview surveys were administered to farmers who supplied information about the history of weed management and yields. The answers to the survey indicated that weedy rice (Oryza sativa L.) and Echinochloa sp. were the most important weeds that occurred in flooded rice areas in RS. Advanced growth stage of weeds and inadequate environmental conditions such as air temperature and relative humidity were listed as the main reasons for the low weed control efficacy. Farmers achieved greater rice yields when adopted rice-soybean [Glycine max (L.) Merr.] (9,140 kg ha−1 average yield) and herbicide site of action rotations (8,801 kg ha−1 average yield) along with tank-mixes (8,580 kg ha−1 average yield) as specific management practices for resistant weed control. The use of glyphosate with residual herbicides in tank-mix in rice spiking stage is the main factor related to greater yields. The postemergence applications and their relations with delaying of flooded rice is a factor that reduces rice yield when no spiking glyphosate applications was made. Identification of the most important weeds in terms of occurrence, as well as the knowledge of the main agronomic practices adopted by the farmers, are essential so that recommendations for integrated management practices can be adopted in an increasingly accurate and sustainable-flooded rice areas in Southern Brazil.

scholarly journals Snorkeling Strategy: Tolerance to Flooding in Rice and Potential Application for Weed Management

Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 975
Author(s):  
Tiago Edu Kaspary ◽  
Nilda Roma-Burgos ◽  
Aldo Merotto
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Potential Application ◽  
Genetic Manipulation ◽  
Weedy Rice ◽  
Flood Tolerance ◽  
Flooding Tolerance ◽  
Cultivated Rice ◽  
Tolerance Mechanisms ◽  
Crop Models

Flooding is an important strategy for weed control in paddy rice fields. However, terrestrial weeds had evolved mechanisms of tolerance to flooding, resulting in new ‘snorkeling’ ecotypes. The aim of this review is to discuss the mechanisms of flooding tolerance in cultivated and weedy rice at different plant stages and the putative utility of this trait for weed management. Knowledge about flooding tolerance is derived primarily from crop models, mainly rice. The rice model informs us about the possible flooding tolerance mechanisms in weedy rice, Echinochloa species, and other weeds. During germination, the gene related to carbohydrate mobilization and energy intake (RAmy3D), and genes involved in metabolism maintenance under anoxia (ADH, PDC, and OsB12D1) are the most important for flooding tolerance. Flooding tolerance during emergence involved responses promoted by ethylene and induction of RAmy3D, ADH, PDC, and OsB12D1. Plant species tolerant to complete submersion also employ escape strategies or the ability to become quiescent during the submergence period. In weedy rice, the expression of PDC1, SUS3, and SUB1 genes is not directly related to flooding tolerance, contrary to what was learned in cultivated rice. Mitigation of flooding tolerance in weeds could be achieved with biotechnological approaches and genetic manipulation of flood tolerance genes through RNAi and transposons, providing a potential new tool for weed management.

Effect of rice establishment methods on weedy rice (Oryza sativa L.) infestation and grain yield of cultivated rice (O. sativa L.) in Sri Lanka

2014 ◽  
Vol 55 ◽  
pp. 42-49 ◽  
Author(s):  
Bhagirath S. Chauhan ◽  
Anuruddhika S.K. Abeysekera ◽  
Manoja S. Wickramarathe ◽  
Sakinda D. Kulatunga ◽  
Upali B. Wickrama
Keyword(s):  
Oryza Sativa ◽  
Sri Lanka ◽  
Grain Yield ◽  
Oryza Sativa L ◽  
Weedy Rice ◽  
Cultivated Rice

Fine mapping of a gene causing hybrid pollen sterility between Yunnan weedy rice and cultivated rice (Oryza sativa L.) and phylogenetic analysis of Yunnan weedy rice

Planta ◽  
2009 ◽  
Vol 231 (3) ◽  
pp. 559-570 ◽  
Author(s):  
Yong Wang ◽  
Zheng Zheng Zhong ◽  
Zhi Gang Zhao ◽  
Ling Jiang ◽  
Xiao Feng Bian ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Oryza Sativa ◽  
Fine Mapping ◽  
Oryza Sativa L ◽  
Pollen Sterility ◽  
Weedy Rice ◽  
Cultivated Rice

scholarly journals Rapid PCD Process Promotes Early Maturity in Weedy Rice (Oryza sativa L. f. spontanea)

2020 ◽  
Author(s):  
Can Zhao ◽  
Wenrong Xu ◽  
Zheng Zhang ◽  
Lingchao Meng ◽  
Weimin Dai ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Oryza Sativa ◽  
Cell Viability ◽  
Grain Filling ◽  
Oxidative Enzymes ◽  
Weedy Rice ◽  
Oxygen Species ◽  
Cultivated Rice ◽  
Early Maturity ◽  
Grain Filling Period

Abstract Background: Shorter grain-filling period and rapid endosperm development contributes to early maturity in weedy rice (Oryza sativa L. f. spontanea). However, the differences in programmed cell death (PCD) process and anti-oxidative enzymes system in the caryopsis between weedy and cultivated rice are largely unexplored. Main Text: we selected four biotypes of weedy rice and associated cultivated rice (ACR, Oryza sativa) from different latitudes to conduct a common garden experiment. The difference of PCD process between weedy rice and ACR was compared by chemical staining, and the cell viability and nuclear morphometry of endosperm cells were observed by optical microscopy, and anti-oxidative enzymes activity were also measured during grain filling. We found that the PCD progress in weedy rice was more rapid and earlier than that in ACR. The percentage of degraded nuclei of weedy rice were 10%-83% higher than that of ACR. Endosperm cells in weedy rice lost cell viability 2-8 days earlier than that in ACR. The anti-oxidant enzymes activity of weedy rice were lower than that of ACR during grain filling. The ability of weedy rice to scavenge reactive oxygen species is weaker than that of ACR, which may contribute to the rapid PCD process in the endosperm cells of weedy rice. Conclusion: The rapid PCD process and weaker ability to scavenge reactive oxygen species in endosperm cells lead to the shorter grain-filling period of weedy rice.

Dormancy-linked Population Structure of Weedy Rice (Oryza sp.)

Weed Science ◽  
2018 ◽  
Vol 66 (3) ◽  
pp. 331-339 ◽  
Author(s):  
Te-Ming Tseng ◽  
Vinod K. Shivrain ◽  
Amy Lawton-Rauh ◽  
Nilda R. Burgos
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Seed Dormancy ◽  
Weed Management ◽  
Production Systems ◽  
Gene Diversity ◽  
Weedy Rice ◽  
Cultivated Rice ◽  
Simple Sequence

AbstractSeed dormancy allows weedy rice (Oryza sp.) to persist in rice production systems. Weedy and wild relatives of rice (Oryza sativa L.) exhibit different levels of dormancy, which allows them to escape weed management tactics, increasing the potential for flowering synchronization, and therefore gene flow, between weedy Oryza sp. and cultivated rice. In this study, we determined the genetic diversity and divergence of representative dormant and nondormant weedy Oryza sp. groups from Arkansas. Twenty-five simple sequence repeat markers closely associated with seed dormancy were used. Four populations were included: dormant blackhull, dormant strawhull, nondormant blackhull, and nondormant strawhull. The overall gene diversity was 0.355, indicating considerable genetic variation among populations in these dormancy-related loci. Gene diversity among blackhull populations (0.398) was higher than among strawhull populations (0.245). Higher genetic diversity was also observed within and among dormant populations than in nondormant populations. Cluster analysis of 16 accessions, based on Nei’s genetic distance, showed four clusters. Clusters I, III, and IV consisted of only blackhull accessions, whereas Cluster II comprised only strawhull accessions. These four clusters did not separate cleanly into dormant and nondormant populations, indicating that not all markers were tightly linked to dormancy. The strawhull groups were most distant from blackhull weedy Oryza sp. groups. These data indicate complex genetic control of the dormancy trait, as dormant individuals exhibited higher genetic diversity than nondormant individuals. Seed-dormancy trait contributes to population structure of weedy Oryza sp., but this influence is less than that of hull color. Markers unique to the dormant populations are good candidates for follow-up studies on the control of seed dormancy in weedy Oryza sp.

Responses of Weedy Rice to Drought Stress at Germination and Seedling Stages

2013 ◽  
Vol 316-317 ◽  
pp. 451-459 ◽  
Author(s):  
Guo Hua Ding ◽  
Xiao Liang Liu ◽  
Dian Rong Ma ◽  
Xiao Xue Wang ◽  
Guang Yang ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Water Stress ◽  
Drought Stress ◽  
Root Length ◽  
Dry Weight ◽  
Shoot Length ◽  
Stress Index ◽  
Weedy Rice ◽  
Fresh Weight ◽  
Cultivated Rice

Drought is a world-spread problem seriously influencing grain production and quality, the loss of which is the total for other natural disasters, with increasing global climate change making the situation more serious. Rice is the staple food for more than 23% of world population, so rice anti-drought physiology study is of importance to rice production and biological breeding for the sake of coping with abiotic and biotic conditions. Much research is involved in this hot topic, but the pace of progress is not so large because of drought resistance being a multiple-gene-control quantitative character. On the other hand, stress adaptive mechanisms are quite different, with stress degree, time course, materials, soil quality status and experimental plots, thus increasing the complexity of the issue in question. Additionally, a little study is related to weedy rice.In order to investigate the effects of drought stress on germination and early seedling growth of weedy rice (Oryza sativa f. spontanea L.) and cultivated rice (Oryza sativa L.), polyethyleneglycol-6000 (PEG-6000) are used to generate -1.33MPa and 0MPa water stress in a laboratory condition (28±3°C). Complete randomized design with three replications is used in the study. After 10 days of germination, shoot length, the longest root length, root fresh weight, root dry weight, shoot fresh weight, shoot dry weight and root numbers are measured; germination percentage, and root to shoot ratio are calculated. Germination index (GI), shoot length stress index (SLSI), root length stress index (RLSI) and dry matter stress index (DMSI) are used to evaluate the response of different genotypes to PEG-induced water stress. Results of ANOVA analysis show that responses of weedy rice accessions and cultivated rice varieties to water stress are significant different, demonstrating the germplasm of weedy rice and cultivated rice are diverse which enables us to screen the germplasm tolerant to drought stress.

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