Assessing Jatropha curcas pollen viability: A comparative assessment of transgenic and nontransgenic pollen under various environmental conditions using rapid staining technique

Kasthurirengan Sampath ¹ Hong Yan ² Srinivasan Ramachandran ^1*

• ¹ Temasek Life Sciences Laboratory, Singapore, Singapore
• ² Nanyang Technological University, Singapore, Singapore

Pollen is the important vector for the transgene flow between non-transgenic plants. Several aspects of pollen biology have been investigated using pollens from X8#34 transgenic and non-transgenic Jatropha, a promising biofuel crop. Pollen viability was assessed through different staining methods and the optimized double staining method with Fluorescein Diacetate (FDA) and Propidium Iodide (PI) for Jatropha , as it can distinguishingly clearly differentiate viable and dead pollen with green and red fluorescent respectively.Among the environmental factors we tested, high temperature (35, 40 & 45°C), significant difference observed from 15 min incubation andperiod and high doses of UV-B irradiation significantly reduced Jatropha pollen viability at 12 and 15 W/m2 dosages. There is no significant difference in pollen viability between X8#34 transgenic Jatropha with non-transgenic counterpart. Under a field relevant sunny condition, pollen viability reduced to 19% in 45 min and 16% viability in non-transgenic, with complete loss of viability in 90 min for both. Under cloudy /shady atmospheric conditions, most of the Jatropha pollens (>97 %) lost their viability in 240 min. Pollen viability assessments showed that there is no statistical difference between two genotypes, X8#34 transgenic and non-transgenic Jatropha across all tested conditions. There is no significant difference in pollen viability of X8#34 transgenic Jatropha with their nontransgenic counterpart. This report is the first study on transgenic Jatropha curcas pollen viability study, we suggest that the optimized double staining technique (FDA+PI) in Jatropha and could serve bd adopted as the baseline for risk assessment of transgenic Jatropha plants.