Large-scale evaluation of maize germplasm for low-phosphorus tolerance.
Low-phosphorus (LP) stress is a global problem for maize production and has been exacerbated by breeding activities that have reduced the genetic diversity of maize. Although LP tolerance in maize has been previously evaluated, the evaluations were generally performed with only a small number of accessions or with samples collected from a limited area. In this research, 826 maize accessions (including 580 tropical/subtropical accessions and 246 temperate accessions) were evaluated for LP tolerance under field conditions in 2011 and 2012. Plant height (PH) and leaf number were measured at three growth stages. The normalized difference vegetation index (NDVI) and fresh ear weight (FEW) were also measured. Genetic correlation analysis revealed that FEW and NDVI were strongly correlated with PH, especially at later stages. LP-tolerant and -sensitive accessions were selected based on the relative trait values of all traits using principal component analysis, and all the 14 traits of the tolerant maize accessions showed less reduction than the sensitive accessions under LP conditions. LP tolerance was strongly correlated with agronomic performance under LP stress conditions, and both criteria could be used for genetic analysis and breeding of LP tolerance. Temperate accessions showed slightly better LP tolerance than tropical/subtropical ones, although more tolerant accessions were identified from tropical/subtropical accessions, which could be contributed by their larger sample size. This large-scale evaluation provides useful information, LP-tolerant germplasm resources and evaluation protocol for genetic analysis and developing maize varieties for LP tolerance.
Institute of Crop Science, National Key Facility of Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing, China.
Hongwei
H
Zhang
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China; Root Biology Center, College of Agronomy, South China Agricultural University, Guangzhou, China.
Ruineng
R
Xu
Institute of Crop Science, National Key Facility of Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing, China.
Chuanxiao
C
Xie
Institute of Crop Science, National Key Facility of Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing, China.
Changling
C
Huang
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China; Root Biology Center, College of Agronomy, South China Agricultural University, Guangzhou, China.
Hong
H
Liao
Institute of Crop Science, National Key Facility of Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing, China; International Maize and Wheat Improvement Center (CIMMYT), El Batán, Texcoco, Mexico.
Yunbi
Y
Xu
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China; Root Biology Center, College of Agronomy, South China Agricultural University, Guangzhou, China.
Jinxiang
J
Wang
Institute of Crop Science, National Key Facility of Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing, China.
Wen-Xue
WX
Li
D000222:Adaptation, Physiological / Q000187:drug effects*; D060146:Ecotype; D040582:Inheritance Patterns / Q000235:genetics; D010641:Phenotype; D010758:Phosphorus / Q000494:pharmacology*; D019655:Quantitative Trait, Heritable; D012639:Seeds / Q000187:drug effects / Q000502:physiology*; D012987:Soil; D013312:Stress, Physiological / Q000187:drug effects; D003313:Zea mays / Q000187:drug effects / Q000235:genetics / Q000502:physiology*
D012987:Soil; D010758:Phosphorus