Root Phenotyping – Andean Diversity Panel

With global climate change, abiotic stresses are receiving considerable attention by plant breeders as there is an immediate need for improving drought and heat tolerance in crops throughout the world.  Dry bean is a major source of protein consumed by the poor and an important source of iron, folate, and other nutrients needed by the human body.  Though significant contributions of improved germplasm have been identified, highly productive and abiotic/biotic stress tolerant common bean varieties are needed in Africa in order to increase production and thereby improve nutrition.

Diversity panels can provide a broad range of germplasm and aid in the exploitation of genes underlying complex traits, such as drought. In this study, the Andean diversity panel (ADP) was evaluated at the Agricultural Research Institute of Mozambique (IIAM) Sussendenga, Mozambique Station in a collaborative research effort with Dr. Magalhaes Miguel (IIAM).

Processing of common bean plants for shovelomics root trait data collection in Sussendenga, Mozambique

Processing of common bean plants for shovelomics root trait data collection in Sussendenga, Mozambique

There is a high genotype by environment interaction for complex traits like drought tolerance and observing lines in different locations is of primary importance.  In Sussendenga, Mozambique, root traits were characterized, including: basal root angle, basal whorl number, basal root number, number of adventitious roots, stem diameter, tap root diameter, and nodule and disease ratings were collected on 287 lines in two replications by Jennifer Trapp (USDA-ARS), Karen Cichy (USDA-ARS), and Jimmy Burridge (Pennsylvania State University).  This data will be analyzed by association mapping using SNP data generated by Dr. Perry Cregan, USDA-ARS, using the BeanCAP SNP chip.

A subset from the 287 lines was grown in a field trial in Othello, WA to further characterize these lines under drought stress.  A total of 31 lines were grown in both locations and combined for root trait analysis.  Six of the 8 traits analyzed showed significant differences among lines and a correlation was computed between Sussendenga and Othello for those significant traits (Table 1).  The high correlation for tap diameter, basal root whorl number, and stem diameter indicate potentially heritable traits that could be useful for plant breeders given further evidence for their association with additional desirable traits.

Table 1. Correlation values for root traits between Sussendenga, Mozambique and Othello, WA.

Trait R2
Minimum Basal Root Angle 0.08
Adventitious Roots 0.06
Tertiary Branching 0.008
Stem Diameter 0.29
Tap Root Diameter 0.32
BRWN 0.32