Foreword

Wheat (Triticum aestivum L.) is the most important food crop worldwide, which provides one-fifth of the protein and calories to more than 4.5 billion people. Yellow rust (also called stripe rust) caused by Puccinia striiformis f. sp. tritici, is one of the most destructive wheat diseases, which can result in significant yield losses or huge investment in chemical control. The extended Himalaya region (such as Nepal, Pakistan and China) is identified as a hotspot of sexual recombination and genetic diversity as well as the putative center of origin of the pathogen, while the Middle East is the center of origin for common wheat along with the source of high-temperature adapted strain. These areas are critical for wheat yellow rust epidemic around the world. Therefore, it is crucial to know the details about wheat yellow rust situation and research progress in these hotspot regions. However, there was a lack of such a comprehensive book regarding wheat yellow rust focusing on these important regions. This was an incentive for us to write this book.

Compilation of information on yellow rust research in these regions is further important due to the potential invasions across these areas and to other parts of the world, as reported in recent past. There is a dire need for collaborative efforts at the regional and global level to anticipate and adopt preemptive measures to avoid such invasions. To initiate such a collaboration, it is highly important to provide a comprehensive background of various research work done in different countries. This provides another reason to compile such a book with contribution from experts from various countries of these regions.

This book, covers the countries such as China, Nepal, Pakistan, Iran, Iraq, and Egypt. Each country is covered in one chapter, then the book includes six chapters, where each chapter addresses the research progress on different aspects of yellow rust. The chapters are arranged considering a rough order of the geographical position of the countries with a direction of east to west. The contents encompass disease epidemiology, host resistance, resistance gene utilization and resistance mechanisms, pathogen population genetic structure, pathogenicity mechanisms, effector proteome, integrated management, as well as future perspectives, etc. Of course, not all the countries had the same level of work in various areas of research and thus the chapters could not be coherent to this extent to give details about all the topics at the same level.

There are many publications on wheat yellow rust from these countries. We tried to summarize the information based on as many as we could but it was impossible to include all. We express our regret to those whose papers are missed in this book. We especially thank the scientists who made great contributions to the great body of knowledge on yellow rust. We do hope that this book will provide helpful information for interested researchers and prompt future cooperation among these countries to combat wheat yellow rust. Finally, we welcome any comments and criticisms to this book.

Mingju Li

Kunming, China

November 10, 2021

Sajid Ali

Mansehra, Pakistan

November 10, 2021