Pollen and spores in yellow rain from Lucknow, northern India

ABSTRACT

This paper presents the results of pollen and spore concentration of yellow drops in the Lucknow environs during the summer of 2014. The yellow spots were procured from the surface of a number of leaves and other objects from three different localities of Lucknow District of Uttar Pradesh. The size and shapes of these spots vary, ranging from linear to circular. Pollen grains recovered in good frequencies chiefly belong to angiosperms, whereas some gymnosperm pollen was also observed in trace frequencies. Other microbiota include fern spores, fungal remains and insect body parts in lower values. The study broadly suggests that palynomorphs recovered from yellow droppings are not fully airborne; rather, they are the types that honey bees gather from crop fields to feed their young. Brassica campestris and Asteroideae are the dominant plant taxa recorded in yellow rain samples. On investigation, it was noticed that yellow drop falling occurred for a few minutes on limited days during the summer of 2014, when the atmosphere experienced optimal temperature conditions with relatively humid environs. The observation also confirms that the yellow spots are nothing but faecal droppings, as suggested by the bee faeces theory which proposed that the origin of yellow rain is a phenomenon of nature. The study, in addition to aiding in understanding yellow rain occurrence, could also be helpful in aerobiological research, especially in examining the allergenicity of various pollen grains/spores in the area of investigation, causing bronchial asthma, hay fever (allergic rhinitis/pollinosis), nasobronchial allergy and other respiratory disorders along with conjunctivitis, contact dermatitis, eczema, food allergies and other health ailments. A multivariate principal component analysis (PCA) was applied to quantified data obtained from pollen frequency analyses of different areas of Lucknow, which clearly revealed a significant group variation in vegetation type on the basis of dispersal and deposition of pollen in yellow spots.

KEYWORDS:

• palynology
• yellow spot
• honey bee
• allergenicity
• Lucknow
• Uttar Pradesh
• India

Acknowledgements

We thank Prof. Sunil Bajpai, Director, Birbal Sahni Institute of Palaeosciences, Lucknow, for providing the necessary facilities and permission for the publication of the manuscript. Thanks are due to local residents of Jankipuram, Triveni Nagar and Nirala Nagar, Lucknow, for sharing their experiences of the event of yellow rain. ST sincerely thanks Mrs Tusha Tripathi for her kind help.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Birbal Sahni Institute of Palaeosciences.

Notes on contributors

Samir Kumar Bera

SAMIR K BERA was awarded a BSc (Hons.) degree in botany from the University of Calcutta in 1976, MSc degree in botany from the University of Burdwan in 1978 and a PhD degree from the University of Lucknow in 1989. He is currently a scientist “F (Retd.)” at the Birbal Sahni Institute of Palaeosciences in Lucknow, working on SERB–DST project on palaeoclimatology based on pollen proxy in Northeast Indian reserve forests. He has 34 years of research experience and has published more than 100 research papers in peer-reviewed national and international journals. He has visited Antarctica twice (1999–2001) and has supervised several research students.

Swati Tripathi

SWATI TRIPATHI is currently working as a scientist-C in the Quaternary Laboratory of the Birbal Sahni Institute of Palaeosciences, Lucknow. Her research interests include quaternary vegetation and climate change through pollen and non-pollen palynomorphs, examining pollen micro-morphometry of living plants, and melissopalynology. She was awarded a BSc degree from Lucknow University in 2005. She received three gold medals including Birbal Sahni Memorial Gold Medal for obtaining the highest percentage of marks in MSc (botany), Lucknow University in 2007. She received her PhD degree in 2011 from the Department of Botany, Lucknow University. She is also the recipient of the Dr B.S. Venkatachala Memorial Medal (2012) and the Dr Chunni Lal Khatiyal Medal (2016) for her outstanding piece of research work as research associate and scientist-B, respectively. She is an associate of the prestigious Indian Academy of Sciences, Bangalore. She has 31 research papers published in peer-reviewed journals. She has trained three MSc students and is currently running a SERB-fast track young scientist project.

Sateesh Chandra Gupta

SATEESH CHANDRA GUPTA was awarded a BSc degree from the Veer Bahadur Singh Purvanchal University Uttar Pradesh in 2011 and MSc degree in biochemistry from the Barkatullah University Bhopal in 2015. He is currently working as a research fellow in Phytochemistry Division, CSIR-National Botanical Research Institute, Lucknow. His research interests include plant metabolomics and statistical analysis.

Sneha Bera

SNEHA BERA graduated with a PhD degree in February 2017 in agriculture from the State Agricultural University (BCKV), West Bengal, India, under the Indian Council of Agricultural Research (ICAR). She received University Gold Medal and Certificate of Excellence for being the topper during her master's degree at BCKV. She received the INSPIRE Fellowship from Department of Science and Technology, Govt. of India and was awarded the Junior Research Fellowship for her research work. During her doctoral program, she was also awarded the prestigious South–North fellowship sponsored by German Academic Exchange Service (DAAD), Excellence Centers for Exchange and Development (EXCEED), and Federal Ministry for Economic Cooperation and Development (BMZ) for visiting as a researcher at the Food Security Centre, University of Hohenheim, Germany. She was also the recipient of the National award Ganga Singh Chouhan Memorial Gold Medal for her contributions in the field of Agricultural Extension. She also worked as a research associate with Shell Global Solutions International B.V. (Netherlands) and the University of Hohenheim (Germany), Research agreement (No. PT51346) in 2015. She is a DST-Senior Research Fellow, Department of Science and Technology, India, since October 2016. She has published 13 research papers and 4 books.