Cassava Root Phenotyping – Towards New Early Bulking Varieties

In Thailand, cassava (Manihot esculenta Crantz) is considered one of the most important economic crops with annual production of around 25 million tons. Cassava is grown not only as a subsistence crop by small farmers, but also as an agro-industrial crop with a well-developed industry and market. The starch-rich roots of cassava have been used as a raw material for producing a lot of high value-added products including starch, modified starch, sweeteners and derivatives for food and non-food applications. The CASSAVASTORE project aims to achieve an in depth understanding of storage root development to create new early bulking cassava varieties for a sustainable bioeconomy. To achieve our project goals, we focus on a diversity panel of approximately 600 cassava genotypes. We will present the impact of abiotic factors (e.g. rainfall, soil and air temperature) on storage root formation using our checker lines ‘KU 50’ and ‘Rayong 9’, which forms the basis to normalize data from different plantings at different time points and subsequently, inform the selection of genotypes with contrasting storage root formation and development for genetic studies. The genetic information will be used to identify loci and genes coding for early bulking of storage roots that will be included in future breeding programs.

For these in-field studies conducted in Thailand, we developed a ‘field video-box’ for imaging the root crowns at 360˚, and a software to analyse root traits such as root diameter, root angles, root shape, etc. Additionally, a sensor network monitors the abiotic factors in the field including air temperature and moisture, rainfall, photosynthetically active radiation, which is completed through soil moistures, -temperatures measurements in different depths, respectively. The information of the sensors will be used to normalize root data of different plantings, and is additionally used to provide information for field management (e.g. irrigation).