Identification of molecular and morpho-physiological markers for assessing drought tolerance in sugarcane

การระบุเครื่องหมายโมเลกุล สัณฐานวิทยา และสรีรวิทยา สำหรับคัดเลือกอ้อยทนแล้ง

Name: Warodom Wirojsirasak

keyword: Association mapping

; Target enrichment sequencing

; Single nucleotide polymorphism

; Drought tolerance

; Morpho-physiological traits

; Stay-green

Abstract: Drought is a significant constraint on sugarcane productivity. Therefore, understanding how different varieties of sugarcane respond to drought stress and identifying the genetic loci controlling drought tolerance traits can facilitate breeding programs and set up molecular markers and morpho-physiological traits for selecting drought-tolerant varieties. In the first study, we conducted a large-scale candidate gene association study of 649 candidate genes across 159 sugarcane genotypes to identify genetic variants underlying agronomic traits and drought tolerance indices, evaluated in both plant cane and ratoon cane under water-stressed (WS) and non-stressed (NS) environments. We identified 197 significant marker-trait associations (MTAs) in 141 candidate genes associated with 18 evaluated traits with the Bonferroni correction threshold (α = 0.05). Out of the total, 95 MTAs in 78 candidate genes and 62 MTAs in 58 candidate genes were detected under NS and WS conditions, respectively. Most MTAs were found only in specific water regimes and crop seasons. These MTAs explained 7.93–30.52% of phenotypic variation. Association mapping results revealed that 34, 59, and 104 MTAs involved physiological and molecular adaptation, phytohormone metabolism, and drought-inducible genes. They identified 19 pleiotropic genes associated with more than one trait and many genes related to drought tolerance indices. The genetic and genomic resources identified in this study will enable the combining of yield-related traits and sugar-related traits with agronomic value to optimize the yield of sugarcane cultivars grown under drought-stressed and non-stressed environments. In the second study, we examined eight morpho-physiological traits to distinguish among 40 sugarcane genotypes categorized into four groups based on significant differences in cane yield under non-stressed conditions and reduction of cane yield under drought-stressed conditions. The study was conducted during the formative stage in a greenhouse, encompassing both control and drought conditions. Hierarchical clustering analysis, utilizing stay-green traits such as higher chlorophyll fluorescence ratio (Fv/Fm), leaf chlorophyll content (SPAD), leaf relative water content (RWC), and lower leaf rolling score (LR), leaf drying score (LD), and drought recovery score (DR), successfully differentiated 9 sugarcane genotypes with high yield potential and low reduction (PHRL) under drought conditions from other groups. Correlation analysis showed significant relationships among cane yield, reduction of cane yield under drought conditions, and the stay-green traits. Our results demonstrated that morpho-physiological traits contributing to the “stay-green” phenotypes could be useful as selection criteria for drought tolerance in sugarcane. Publisher Thammasat University

Thammasat University. Thammasat University Library

Address: BANGKOK

Email: preserv@tu.ac.th

Name: Kittipat Ukotkij

Role: advisor

Created: 2024

Modified: 2024-11-23

Issued: 2024-11-23

วิทยานิพนธ์/Thesis

application/pdf

DOI: 10.14457/TU.the.2023.437

eng

DegreeName: Doctor of Philosophy

Level: Doctoral Degree

Descipline: Biotechnology

Grantor: Thammasat University

©copyrights Thammasat University

ลำดับที่.	ชื่อแฟ้มข้อมูล	ขนาดแฟ้มข้อมูล	จำนวนเข้าถึง	วัน-เวลาเข้าถึงล่าสุด
1	15595Warodom.pdf	7.5 MB

ใช้เวลา

0.031499 วินาที