Phenotyping for Drought Tolerance in Grain Crops

Flashcards about drought tolerance in grain crops.

Why is breeding for drought tolerance in grain crops not a generic issue?

Periods of drought vary in length, timing and intensity, and different traits are important with different types of drought.

What are the main stages of a crop's life during which drought tolerance can be targeted?

Establishment, vegetative development, floral development, and grain growth.

What is the challenge in phenotyping for drought tolerance?

To devise inexpensive and effective ways of identifying promising phenotypes with the aim of aligning them with genomic information to identify molecular markers useful to breeders.

Who introduced the terms 'genotype' and 'phenotype' into the English language?

Johannsen

According to the notes, what traits are essential for crop plants?

Grain quality, resistance to the most important diseases, and developmental alignment with the target environments.

According to Bänziger et al. (2006), how can heritability for water-limited yield in maize be increased?

By using carefully manipulated droughts.

Who generally has their own operational meanings for the term 'drought'?

Geographers, meteorologists, insurers, breeders, agronomists, plant physiologists and molecular biologists.

What are the two meanings of 'drought tolerance' within the plant sciences, as mentioned in the notes?

The ability to survive severe water deficits and the ability of crops to use most effectively a limited water supply.

What is the most important physiological trait in water-limited environments?

The timing of flowering.

What are the two broad classes into which approaches for improving the yields of droughted crops can be divided?

Survival of severe water deficits and productivity issues that relate to the capture of available water and its most effective use.

What type of genes are typically used in transforming plants for studying the genetics of plants exposed to severe water deficits?

Genes whose expression is postulated to protect plants or cellular functions from severe water stress.

What abiotic stress can markedly reduce floral fertility?

Low water potential during pollen mother cell meiosis and shortly before and after anthesis.

In general, what type of genotypes perform well in the field whenever there is adequate water in the subsoil?

Genotypes that keep growing fast in the face of a decreasing water supply.

What morphological traits are important for optimizing water balance to achieve water-limited potential yield?

Unproductive tillers in cereals and root architecture.

What traits improve water-limited yield?

Long coleoptiles, rapid ground cover, and leaf architecture.

What yield-determining processes are difficult to mimic using pot experiments in controlled environments?

The slow extraction of water from subsoil that often takes place over several weeks.

What type of measurements are more useful than spot measurements in elucidating the main influences on water-limited yield?

Integrative measurements.

What is prebreeding?

All activities designed to identify desirable characteristics and/or genes from unadapted materials to produce new varieties for farmers

In commercial breeding programs, selection is strongly driven by the essentials of what?

Disease resistance, grain quality, and right flowering time.

Where will new ideas for traits effective in water-limited environments come from?

Observations of field scientists