Phenotyping of Weedy Rice to Assess Root Characteristics Associated with Allelopathy  

作　　者：Brooklyn Schumaker Shandrea Stallworth Auriana Tucker Ziming Yue Te-Ming Tseng Brooklyn Schumaker;Shandrea Stallworth;Auriana Tucker;Ziming Yue;Te-Ming Tseng(Department of Plant and Soil Sciences, Mississippi State University, Mississippi State, MS, USA)

机构地区：[1]Department of Plant and Soil Sciences, Mississippi State University, Mississippi State, MS, USA

出　　处：《American Journal of Plant Sciences》2021年第8期1210-1221,共12页美国植物学期刊（英文）

摘　　要：Weedy rice is a species of <i>Oryza</i>,<span> </span>and is a wild relative of cultivated rice. The weed possess</span><span style="font-family:"">es</span><span style="font-family:""> unique hardiness that allows them to thrive in dynamic and stressful environments. These characteristics suggest that weedy rice is a stored source of novel genes for competitive traits. One such trait is allelopathy, where a species releases secondary metabolites that suppress the growth and development of neighboring species. Weed competition is a limiting factor in rice production systems;therefore, it is critical to identify specific allelopathic weedy rice accessions to determine the genetic pathways and mechanisms associated with allelopathy to be used in breeding programs. Due to the complex nature of allelochemical production and the lack of knowledge of allelopathy mechanisms in weedy rice, phenotypic traits, particularly root traits, can be used to overcome this limitation and serve as target characteristics for breeding weed suppressive rice varieties. Five weedy rice accessions were chosen from preliminary screenings of larger sample sizes with the ability to suppress barnyardgrass weed seedling growth. Another five weedy rice with low barnyardgrass suppression was selected for the current root phenotypic study. Five cultivated rice lines were used as a comparison. All plants were propagated in a transparent germination pouch for four weeks. Roots were scanned and analyzed for root length and area covered. No differences were found in the seedling root area among weedy rice and rice accessions;however, allelopathic weedy rice plants exhibited a 14% increase in root length than non-allelopathic weedy rice plants. The allelopathic weedy rice accession B2 possessed the most extended root system (22.4 cm root length). The highly allelopathic weedy rice accessions (including B2) screened and phenotyped in this study are ideal candidates for identifying the genetic controls of early root length, a possible trait contributingWeedy rice is a species of <i>Oryza</i>,<span> </span>and is a wild relative of cultivated rice. The weed possess</span><span style="font-family:"">es</span><span style="font-family:""> unique hardiness that allows them to thrive in dynamic and stressful environments. These characteristics suggest that weedy rice is a stored source of novel genes for competitive traits. One such trait is allelopathy, where a species releases secondary metabolites that suppress the growth and development of neighboring species. Weed competition is a limiting factor in rice production systems;therefore, it is critical to identify specific allelopathic weedy rice accessions to determine the genetic pathways and mechanisms associated with allelopathy to be used in breeding programs. Due to the complex nature of allelochemical production and the lack of knowledge of allelopathy mechanisms in weedy rice, phenotypic traits, particularly root traits, can be used to overcome this limitation and serve as target characteristics for breeding weed suppressive rice varieties. Five weedy rice accessions were chosen from preliminary screenings of larger sample sizes with the ability to suppress barnyardgrass weed seedling growth. Another five weedy rice with low barnyardgrass suppression was selected for the current root phenotypic study. Five cultivated rice lines were used as a comparison. All plants were propagated in a transparent germination pouch for four weeks. Roots were scanned and analyzed for root length and area covered. No differences were found in the seedling root area among weedy rice and rice accessions;however, allelopathic weedy rice plants exhibited a 14% increase in root length than non-allelopathic weedy rice plants. The allelopathic weedy rice accession B2 possessed the most extended root system (22.4 cm root length). The highly allelopathic weedy rice accessions (including B2) screened and phenotyped in this study are ideal candidates for identifying the genetic controls of early root length, a possible trait contributing

关 键 词：Weed Suppression Sustainable Agriculture Integrated Weed Management BARNYARDGRASS Root System Architecture 

分 类 号：S51[农业科学—作物学]