PowerPoint Presentation

PP 503: Physiological and molecular responses of plant to abiotic stresses (2+1)

Large genotypes by environmental interaction (G x E) for yieldPresented by: Ekatpure Sachin Chandrakant (PhD Research Scholar)

DefinitionThe term GE interaction can be defined as the variation in relative performance of genotypes in different environments

Term discovered by Allard and Bradshaw

IntroductionClimate changes may result in strong impacts on agriculture, specially on crop growth and yield

Crops are largely determined by climate conditions during growing season

Even minor deviations from optimal conditions can seriously threaten yield

Therefore, knowledge on the effect of environmental factors on crop growth and development could reduce the possibilities of significant yield loss and improve the selection of specific cultivars for growing in the target regions.

Role of the environment in Quantitative InheritanceThe main result of this effect is that the relationship between genotype and phenotype is partially or completely hidden i.e. the phenotype doesnt reveal the genotype

For e.g: Phenotype = Genotype + Environment ( P = G + E )

If environment = 0 then phenotype = Genotype

However the effect of environment is seldom zero

So phenotype is the joint action of Genotype and Environment

Role contIn crop improvement, the breeder selects plants on the basis of their phenotype

The effectiveness of selection depend on the proportion of phenotype due to the genotype

Therefore, it is important to know the extent to which environment influences different quantitative characters

To estimate the effect of environment on a character, large No. of strain / genotypes are grown in a replicated trial and the data is subjected to analysis of variance as per the experimental design used.

Role contThe genotype x Environmental interaction signifies that the relative performance of various genotype in effected by the environment

For eg: Performance of genotype A may be superior to the genotype B in one environment but in another environment inferior to that of B

If G X E interaction is absent, genotype A will be superior than B in all the environments

Methods for analyzing GE interaction In field crop trials, interaction is often analyzed by

AMMI (additive main effects and multiplicative interaction) model

Analysis of variance (ANOVA)

Principal component analysis (PCA)

Genotype (G) main effect plus GE interaction (GGE)

Biplot analysis

These models have been developed and applied over the years to analyze GE interaction and especially yield stability over environments in different crops

THANK YOU

Seed yield per plant is one of the main yield components which is greatly influenced by genotype, environment and complex genotype by environment interactions