Assessing the Weed-Suppressing Potential of Cotton Chromosome Substitution Lines Using the Stair-Step Assay

Abstract

Palmer amaranth is a problematic common weed species, especially in cotton. With the wide use of chemical herbicide and herbicide-tolerant transgenic cotton lines, Palmer amaranth populations have developed tolerance to commonly used herbicides. It is imperative to develop alternative weed control methods to slow the evolution of herbicide-resistant weed populations and provide new strategies for weed management. Eleven chromosome substitution (CS) cotton lines (CS-B26lo, CS-T17, CS-B16-15, CS-B17-11, CS-B12, CS-T05sh, CS-T26lo, CS-T11sh, CS-M11sh, CS-B22sh, and CS-B22lo) were screened for weed-suppressing abilities in this study. The cotton lines were tested using the established stair-step assay. Height (cm) and chlorophyll concentration (cci) were measured for each plant in the system. The most significant variation in Palmer amaranth height reduction among the CS lines was observed 21 days after establishment. CS-B22sh (76.82%) and T26lo (68.32%) were most effective in reducing Palmer amaranth height. The cluster analysis revealed that CS-B22sh, and CS-T26lo were clustered in one group, suggesting similar genetic potential with reference to Palmer amaranth growth and development. CS-B22sh showed novel genetic potential to control the growth and development of Palmer amaranth, a problematic weed in cotton fields. Future experimentation should implement more parameters and chemical testing to explore allelopathic interactions among CS lines and Palmer amaranth.

Assessment of Allelopathic Potential of Cotton Chromosome Substitution Lines

“…PCA and clustering have been used to group allelopathic weed-suppressive cotton lines based on their weed-suppressive potential, which can aid in gaining a deeper insight into breeding material for crop enhancement (Fuller et al, 2021) [2]. Similarly, the grouping of rice cultivars by Schumaker et al (2020) [19] and sweet potato varieties by Singh et al (2022) [25] has been carried out using similar strategies.…”

“…Providing approximately 35 percent of global cotton exports in recent years, the United States is the world’s leading cotton exporter. Among the U.S. States, Texas is the largest producer, accounting for approximately 40 percent of U.S. cotton production, with other top producers being Georgia, Mississippi, and Arkansas [ 2 ]. The plant is also a known source of valuable chemical compounds, including fatty acids, lipids, carbohydrates, and phenolics [ 2 ].…”

“…Among the U.S. States, Texas is the largest producer, accounting for approximately 40 percent of U.S. cotton production, with other top producers being Georgia, Mississippi, and Arkansas [ 2 ]. The plant is also a known source of valuable chemical compounds, including fatty acids, lipids, carbohydrates, and phenolics [ 2 ]. Cotton fibers produce various consumer goods, including oils, paper products, animal feed, and textiles [ 3 ].…”

“…Palmer amaranth (PA) and other weeds in cotton fields have historically been controlled by suitable cultivation, pre-planting, and timed herbicide applications (pre-emergence and postemergence herbicide application) [ 2 , 8 ]. Herbicides, often known as weedkillers, are pesticides used to manage undesirable plants in fields such as agriculture, forestry, gardening, and landscaping [ 9 , 10 , 11 ].…”

Use of Plant Secondary Metabolites to Reduce Crop Biotic and Abiotic Stresses: A Review

“…According to preliminary studies on cotton allelopathy [39], cotton root showed significant quantities of four phenolic chemicals, including p-hydroxybenzoic acid, ferulic acid, gallic acid, and vanillin. A greenhouse study was conducted using eleven cotton chromosome substitution (CS) lines for allelopathy screening against Palmer amaranth (Amaranthus palmeri) (PA) [40]. The cotton lines were tested using a modified stair-step assay.…”