Chilling stress effects on reproductive biology of chickpea

Chickpea is sensitive to chilling temperatures (<10°C),especially at its reproductive phase leading to floralabortion. The exact causes of reproductive failures arenot fully understood. In the present study, we assessed thecold-induced damage to development and functioning ofmale and female components by growing an earlyflowering chickpea genotype ICCV 96029 under warmconditions of the glasshouse (control; average maximumand minimum temperature ?28/15°C) as well as undercold conditions of the field (average maximum andminimum temperature ?20/10°C during reproductivephase). Low temperature of the field environmentrestricted the vegetative growth and delayed all thephenological stages in comparison to control plants.Apart from this, it led to some vegetative aberrations likechlorosis, necrosis of leaf tips and curling of whole leaf.The damage to reproductive stage involved abscission ofjuvenile buds and flowers and abortion of pods. On thewhole, pollen development at young microspore stageappeared to be severely affected in stressed conditionscompared to the control conditions. Pollen viability wassuppressed during stressed conditions (60%) comparedto normal plants (95%). Stigma receptivity, in vivo pollengermination and pollen tube growth were inhibited in thestressed plants. Fluorescent studies showed that thestigma either did not show any pollen load or pollengrains did not germinate on its surface in stressed plants.Even when the pollen grains germinated, the pollen tubesrarely grew beyond the proximal region of the style;mostly the pollen tubes were impaired in their growth anddid not reach the ovules leading to failure in fertilization.The egg and secondary nucleus in such ovules ultimatelydisintegrated without fertilizing and hence no seedformation occurred

S Kumar, H Nayyar, R K Bhanwara, H D Upadhyaya, 'Chilling stress effects on reproductive biology of chickpea', Journal of SAT Agricultural Research, vol. 8, pp.1-14, International Crops Research Institute for the Semi-Arid Tropics, 2012