Root growth in Jatropha and its implications for drought adaptation

• Published in: Biomass & bioenergy 2012-04, Vol.39, p.247-252
• Main Authors: Krishnamurthy, L., Zaman-Allah, M., Marimuthu, S., Wani, Suhas P., Kesava Rao, A.V.R.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Drought avoidance; Economic plant physiology; Fundamental and applied biological sciences. Psychology; Jatropha curcas; Monolith method; Morphology. Anatomy. Histology. Cytology; Root anatomy; Root length density; Root to total plant ratio; Trench wall method
• ISSN: 0961-9534; 1873-2909
• DOI: 10.1016/j.biombioe.2012.01.015

The relative drought tolerance of Jatropha curcas is, so far, not very well understood. To understand its physiological adaptation to drought-stress, the root growth viz; root length density (RLD), root dry weight (RDW), biomass accumulation and resources allocation for roots of adult trees grown in the field were assessed. The tap root in Jatropha branches perpendicular to the ground with many lateral roots. The rooting depth was 1.4 m with a greater root length distribution at the surface soil. It depicted a low root to plant ratio when the tap root was not included. The root branching in Jatropha suggested that it may help containing soil erosion although its contribution to drought tolerance is seemingly conservative. The drought response of Jatropha can be categorized as drought avoidance, considering its regular dormant state, drought-stress induced leaf drop and a limited root growth. Jatropha curcas, a perennial shrub is a useful plant for biofuel production and rehabilitation of degraded lands in the tropics. The relative drought tolerance of J. curcas is, so far, not very well understood. To understand its physiological adaptation to drought-stress, the root growth viz; root length density (RLD), root dry weight (RDW), biomass accumulation and resources allocation for roots of adult trees grown in the field were studied. [Display omitted] ► Jatropha curcas roots branch profusely at surface soil and are relatively shallow. ► The root to shoot ratio was exceptionally poor when tap root was not considered. ► The fine roots had greater cortex than stele with a few expanded xylem vessels. ► The root growth of Jatropha indicates its drought avoidance strategy. ► The rooting depth extension and the soil water depletion were slow in Jatropha.