TITLE:
Allelochemicals as Growth Stimulators for Drought Stressed Maize
AUTHORS:
Nazimah Maqbool, Rumana Sadiq
KEYWORDS:
Sorgaab, Stimulator, Low Dilutions, Sorghum Water Extract
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.8 No.5,
April
17,
2017
ABSTRACT: Sorgaab, an aqueous extract of sorghum leaves was
applied to probe the modulation in growth and physiological attributes of maize
under drought in lab and greenhouse studies. Sorgaab soaked seeds (10
dilutions) were germinated to assess drought tolerance at germination and
seedling growth stages. More concentrated Sorgaab solutions (2 mL·L-1) were damaging, while lower concentration in the range of 0.75 to 1.5 mL·L-1 improved the root and shoot growth of maize under drought. Applied
drought stress decreased chlorophyll b greater than chlorophyll a that improved
the chl a/b ratio. Application of Sorgaab also improved the internal CO2 assimilation, which increased the net photosynthesis and A/E ratio of drought affected
plants. Soluble phenolics and anthocyanins were also more increased in plant
receiving Sorgaab under drought than control. Although greater concentrations
of phenolic acids inhibit the uptake of ions, but its lower concentrations
stimulate the uptake of K+, Ca2+, NO3, PO4.
In conclusion, although high concentrations of Sorgaab reduced the growth of plants, it might alleviate the adverse
effects of drought, if applied at the low concentration. Dilute concentrations of Sorgaab
can be utilized as a natural source for improving drought resistance in maize
both at germination and later growth stages.