Could the reliability of classical descriptors of fruit quality be influenced by irrigation and cold storage? The case of mango, a climacteric fruit

BACKGROUND: Large improvements have been realized on the accuracy of the determination of fruit quality. The relevance of the relationship between commonly used quality descriptors and their related chemical contents was here questioned under the influence of water supply reduction and postharvest cold storage. The study relied on three analyses: (1) a correlation table between quality descriptors and compound contents, (2) principal component analysis using the selected variables to see the quality discrimination dictated by treatments; and (3) linear correlation between content and descriptors according to treatments. RESULTS: The results indicate that abiotic parameters applied on mango fruits before or after harvest can affect the relationship between a quality descriptor and the content in compounds it is related to, here between titratable acidity and organic acid content and to a lesser extent between color, represented by hue angle values, and carotenoids, possibly creating bias in the final quality determination. A stronger relation between total soluble solids and total sugar content, were observed under mild abiotic stress. CONCLUSION: Fruit growth and postharvest storage conditions, such as irrigation and cold storage, can influence the actual correspondence between the compounds contents and the descriptors used to estimate fruit quality, particularly for pulp color, sugars and acids

Architectural analysis of root system of sexually vs. vegetatively propagated yam (Dioscorea rotundata Poir.), a tuber monocot

A-09-11International audienceArchitectural descriptors were used to understand root system structure and development in white yam (Dioscorea rotundata Poir., Dioscoreaceae), a tuber monocot. Observations were made on seedlings and plant derived from tuber fragments, cultivated in greenhouses over a developmental cycle. This study demonstrated that both seedlings and plants derived from tubers have two distinct root systems that are highly organized. The first (seminal or tubercular) has been called the temporary root system which is small and short lived. The architectural unit here is made up of two root axis categories. The second (adventitious in both cases) has been called the definitive root system. It is larger and has a far longer lifespan than temporary root systems. The architectural unit here is made up of three root axis categories. Adventitious root systems are formed by structural repetitions of their own architectural unit. The temporary and definitive root systems possess the same structural and functional properties and become established and succeed one another in time following an identical developmental sequence. Neo tuber development is coupled with the root system development. Our results highlight to what extent it is important to study simultaneously the different parts of a root system in order to understand its development. This study confirms how architectural tools can be used to understand root system structure and development and prove accurate informations on root system development for use in agricultural management