International Symposium on Cereal Leaf Blights 2019 | University College Dublin, Ireland | 22-24 May 2019

Effect of Spot Blotch and Heat Stress on Fitness and Yield Parameters of Spring Wheat


Ramesh Chand*
Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221005, India

Ranjan Chaubey
Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221005, India

Sudhir Navathe
Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221005, India
Agharkar Research Institute, G.G. Agharkar Road, Pune 411004, India

D D Bhutuia
Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221005, India

Vinod Kumar Mishra
Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221005, India

Pawan Kumar Singh
International Maize and Wheat Improvement Center (CIMMYT) Apdo. Postal 6-641 Mexico DF Mexico

Uttam Kumar
Borlaug Institute for South Asia (BISA), G-2, B-Block, NASC Complex, DPS Marg, New Delhi 110012 India.

Arun Kumar Joshi
International Maize and Wheat Improvement Center (CIMMYT), G-2, B-Block, NASC Complex, DPS Marg, New Delhi 110012 India
Borlaug Institute for South Asia (BISA), G-2, B-Block, NASC Complex, DPS Marg, New Delhi 110012 India.


Poster Presentation
Special Topics

Atrium, UCD O'Brien centre for Science
Poster 51

View this abstract online by visting isclb2019.com/see/ABS48238

Spot blotch (caused by Bipolaris sorokiana) and terminal heat stress are the two major issues for substantial yield reduction and economic losses of wheat in the warm and humid regions of the world particularly EGP of South-Asia where wheat is grown in around 10 million hectares. An investigation was conducted with an aim to determine the combined effect of terminal heat stress and spot blotch of wheat. Fifty five diverse wheat genotypes were grown in two dates of sowings (timely and late sown) under two treatments - inoculated with B. sorokiana and protected with azoxystrobin during 2016-17 and 2017-18. The experiment was aimed to observe the combined effect of terminal heat stress and spot blotch on wheat in relation to membrane damage and effect on grain characters and various quantitative traits such as plant height, spike length, thousand kernel weight, biomass and grain yield as well as several and physiological traits (chlorophyll content, waxiness index, NDVI, MSI and MDA). The study revealed oxidative damage due to combined stress of spot blotch and terminal heat stress that caused increase in MDA content leading to greater damage to membrane that was further responsible for increased electrolytic leakage. MSI was lower in susceptible genotypes. AUDPC had significant positive correlation with lower values of AU(SPAD)DC and AU(NDVI)DC under both timely and late sown conditions. The decrease in chlorophyll content was 20% due to combined effect of spot blotch and heat stress. Reductions in various grain traits due to combined or individual effect of spot blotch and heat stress was obtained. For instance, the combined effect of two stresses caused 63% reduction in biomass whereas spot blotch alone caused 38% reduction. Study revealed that spot blotch along with terminal heat is causing significant yield losses and therefore both need due attention by wheat breeders.