The Damage by Weedy Rice — Can Feral Rice Remain Undetected?

Valverde, Bernal E.

doi:10.1201/9781420037999.ch17

Cited by 18 publications

(16 citation statements)

References 49 publications

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“…). Fast growth, efficient use of nutrients, resistance to drought, early grain shattering, and pronounced seed dormancy render weedy rice highly problematic (Valverde ; Delouche et al. ; Shivrain et al.…”

Section: Introductionmentioning

confidence: 99%

Microsatellite markers reveal multiple origins for Italian weedy rice

Grimm

Fogliatto

Nick

et al. 2013

Ecology and Evolution

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Weedy rice (Oryza sativa L.) is one of the major issues of rice cultivation worldwide. In Italy, it infests about 70% of the total rice area. Different Weedy Rice populations can be distinguished based on variable morphological and physiological traits; however, little is known about genetic differentiation and origin of Italian weedy rice populations. The objective of this study was to genetically and morphologically characterize and compare different Italian weedy rice populations selected on the basis of different phenotypes. The main Italian rice territory was divided into 10 geographical areas in which 40 weedy rice populations were collected and grouped according to the awn traits. All the individuals of the populations were morphologically characterized according to plant and seed traits. Genetic characterization was performed using 19 SSR markers on all the collected accessions, and several rice cultivars, including some very old (late 19th century), nowadays are no longer cultivated. ANOVA showed that morphological plant and seed traits were significantly affected by the collection area and awnedness group. The importance of the awn morphology was also reflected in the Bayesian clustering where, despite a relatively low genetic diversity, the clusters displayed different awn types. An UPGMA dendrogram confirmed the clusters detected in STRUCTURE analysis and also revealed a grouping of certain old cultivars with the weedy rice, suggesting a common origin.

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Section: Introductionmentioning

confidence: 99%

Microsatellite markers reveal multiple origins for Italian weedy rice

Grimm

Fogliatto

Nick

et al. 2013

Ecology and Evolution

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“…The movement to direct seeding, the establishment of the rice crop by sowing seeds in the field as opposed to transplanting, has brought weedy (also called feral, or red) rice to the fore, most recently in Asia (Table 1). Weedy rice is very difficult to control in rice because it is con‐specific to the crop (also Oryza sativa ) 1. There are other weedy Oryza species, most of them belonging to the same AA genome group as the crop.…”

Section: Introduction—the Problemsmentioning

confidence: 99%

A strategy to provide long‐term control of weedy rice while mitigating herbicide resistance transgene flow, and its potential use for other crops with related weeds

Gressel

Valverde

2009

Pest Management Science

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Transgenic herbicide-resistant rice is needed to control weeds that have evolved herbicide resistance, as well as for the weedy (feral, red) rice problem, which has been exacerbated by shifting to direct seeding throughout the world-firstly in Europe and the Americas, and now in Asia, as well as in parts of Africa. Transplanting had been the major method of weedy rice control. Experience with imidazolinone-resistant rice shows that gene flow to weedy rice is rapid, negating the utility of the technology. Transgenic technologies are available that can contain herbicide resistance within the crop (cleistogamy, male sterility, targeting to chloroplast genome, etc.), but such technologies are leaky. Mitigation technologies tandemly couple (genetically link) the gene of choice (herbicide resistance) with mitigation genes that are neutral or good for the crop, but render hybrids with weedy rice and their offspring unfit to compete. Mitigation genes confer traits such as non-shattering, dwarfism, no secondary dormancy and herbicide sensitivity. It is proposed to use glyphosate and glufosinate resistances separately as genes of choice, and glufosinate, glyphosate and bentazone susceptibilities as mitigating genes, with a six-season rotation where each stage kills transgenic crop volunteers and transgenic crop x weed hybrids from the previous season.

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“…To make things worse, many weedy rice strains have colored (red to brownish) grain that contaminates the final product. Because of consumer rejection, rice mills have to provide additional polishing to the grain to get rid of the color, reducing nutrients in the entire rice batch and the grain becomes prone to breaking, further reducing the value of the crop (Valverde 2005).…”

Section: Herbicide-resistant Echinochloa Speciesmentioning

confidence: 99%