Please use this identifier to cite or link to this item: http://prr.hec.gov.pk/jspui/handle/123456789/9539
Title: HOST PLANT RESISTANCE:
Other Titles: CONCEPT AND SIGNIFICANCE
Authors: Muhammad Salim, Salim
Keywords: PLANT RESISTANCE
PLANT RESISTANCE CONCEPT
PLANT RESISTANCE SIGNIFICANCE
Issue Date: 2018
Publisher: Higher Education Commission – Pakistan
Abstract: Shrinking area under cultivation mainly due to urbanization and industrialization, declining natural resource base, increase in yield losses incurred by insect pests, and rapidly increasing human population necessitate enhancing productivity of crops to achieve the objectives of food security and poverty alleviation of farming community in Pakistan and other developing countries. New human interventions have in most of the cases been successful to achieve such objectives but only temporarily. With the passage of time, these interventions resulted in to a number of new problems. For example the discovery of insecticidal activity of DDT and its sister compounds in1940s was a major break through in the history of pest control and it was believed that these pesticides would solve the problems of insect pests. Initially pesticides were so powerful tool and man used this tool so massively that the term pest control became synonymous to the chemical control. However, due to indiscriminate use or miss-use of pesticides, multifarious and multi-facet complex problems emerged such as resurgence of target pests, outbreak of secondary pests, environmental pollution, pesticide residues in the produce, bio-magnification of pesticides in food chains and food webs, disturbance in the natural balance, and destruction of bio-control agents and other beneficial organisms. The solution of these problems became very difficult. Likewise, a quantum jump in crop yields, especially those of rice and wheat was obtained through Green Revolution in 1960s due to the cultivation of high yielding crop varieties and increase in input use. In short span of time it was realized that Green Revolution gave birth to certain serious problems including increase in the in the population of insect pests in different crop production systems especially in cotton. As per estimates, environmental and social cost to the country was in the tune of US dollar 206 million per year. Some efforts have been made to develop and implement integrated pest management (IPM) in Pakistan to minimize the losses incurred by insect pests and to solve pesticide- induced problems. This approach was unbalanced because very less emphasis was laid on the development and cultivation of resistance varieties as compared to other components of IPM. It is well established fact that the use of resistant varieties represents one of the simplest and most convenient tactics of insect pest management. In general, the pest management offered by resistant varieties is sustainable and without any extra cost to the growers, is compatible with other components of IPM and helpful to improve the natural balance not only in agro-ecosystems systems but also in whole agricultural matrix, minimizes and in certain cases eliminates the use of pesticides, and proves helpful to achieve stability and sustainability in crop production systems. It is, therefore, imperative to give pivotal position to host plant resistance in IPM. Insect resistant varieties provide substantial economic returns on investment on research and development and give much greater returns on investment than pesticides. It has been estimated that the multiple insect resistant rice variety IR36 has provided US 10 dollars one billion additional annual incomes to rice producers and processors in South and South Asia. Likewise, resistant cultivars of alfalfa, corn, beet and cotton gave lot of benefits to growers. The usefulness of host plant resistance is increasing with the passage of time due to advancement in science and technology. Initially, resistant varieties were developed through Mendelian and biometrician approaches, where the gene pool was very narrow due to the ability of manipulating only primary and secondary gene pools of cultivated species for crop improvement. In certain cases, genes for resistance were not available in the primary and secondary gene pools. Moreover, development of resistant variety took very long time. Real breakthrough in broadening the gene pool, reducing the time of incorporation of resistant genes into target material and to develop varieties with high level of resistance was obtained through biotechnological approaches especially that of genetic engineering. Now scientists are well equipped to identify, conserve, preserve and incorporate resistant genes from diverse sources such as viruses, bacteria, animals and unrelated plant specie into the commercial varieties or promising candidate varieties to develop cultivars with high level of resistance against major insect pests of different crops. Due to rapid pace of research, augmented sophisticated instrumentation and techniques, there has been a tremendous progress in basic and applied aspects of host plants resistance in recent years. It is the need of hour to bring Gene Revolution in Pakistan for the improvement of crops in general and to develop crop varieties with high level of resistance against insects and other pests in particular. I do hope, the book will be helpful to improve the level of knowledge of readers on host plant resistance and would facilitate the teachers and scientists in the preparation and implementation of projects on the subject. The book consists of ten chapters, covering basic and applied aspects of host- plant resistance. First chapter deals with plant-insect interactions concepts, history and definitions of host plant resistance and pre-requisites for the implementation of programme on host plant resistance. In chapter two, mechanism of resistance in plants against insect pests has been explained keeping in view the ecological basis, evolutionary process, trophic levels, mode of inheritance, crop stage, screening conditions, biotype reactions, nature of genes, functional categories of resistance. Chapter three, deals with behavioural and physiological basis of host plant selection. In chapter four, information has been given relating to theories of host plant selection by insects, host plant defence theories and theories of co-evolution of plants and insects. Chapter five deals with important morphological or bio-physical traits of plants which impart resistance against insect pests. Chapter six gives information on biochemical basis of resistance in plants against insect pests of major crops with specific examples from Pakistan. Chapter seven deals with factors/stresses such as salinity, temperature, relative humidity, light, hormones, nutrient deficiencies, nutrient toxicity or excessive amounts of nutrients which affect the level of resistance/susceptibility in crop plants against insect pests. In chapter eight, approaches/techniques for the development of resistant varieties to insect pests have been briefly described. It also contains information on the level of resistance of crop varieties against major insect pests in Pakistan. Information on the genetics of insect resistance in crop plants is given in chapter nine. Strategies to prolong the utility of major geneses are also discussed in this chapter. Chapter ten provides information on the role of host plant resistance in pest management 11 and its compatibility with other components of IPM. In addition, the book contains glossary of important terms and technical index for the benefit of readers. It is not possible to mention all the names that have been helpful for the completion of this book; therefore, I intend to thank all of them. I am thankful to Mr. Saleem Akhtar for doing tiresome work of typing the manuscript and that of Mr. F.D. Shahzad for assisting in search of literature and critically reading the manuscript. My special thanks are due to Mr. Ashfaq, KPO, NARC for his help at different stages in the preparation of book. I am thankful to Mr. M. Younis, PSO and Mr. M. Ayoob, KPO, NSCRI, Thatta and Mr. Zhou Xu Sheng for extending help in the preparation of technical index. I express my gratitude to Dr. H.I. Javed, NARC, Islamabad for his valuable suggestions for the improvement of manuscript and for providing a list of maize varieties resistant to insect pests alongwith some pictures. My thanks are due to Dr. Amjid, Oilseed Research Programme; Dr. A. Rehman, Rice Research Programme; Dr. M. Zubair, Sugar Crops Research Programme, NARC, Islamabad for providing list of resistant varieties to insect pests of their respective crop. Dr. Amjid also offered some useful pictures to be included in the book. The cooperation of PSD, PARC scientists especially Dr. Muhammad Munir is highly appreciated. I express my gratitude and sincere thanks to Dr. M.E .Tusneem, ex-Chairman PARC for his encouragement, valuable guidance and for according permission to write this book. The technical review and suggestions for the improvement of book by both the experts are gratefully acknowledged. Higher Education Commission (HEC), Islamabad is gratefully acknowledged for providing incentive and making arrangements for the evaluation and publication of book. Finally heart-full gratitude to my loving wife Dr. Kausar Parveen; daughters- Dr. Fatimah Zahra, Dr. Amina Mobeen and sons- Dr. Muhammad Bilal and Dr. Abdul Shakoor for their help and encouragement in the completion of book. I thank Allah (SWT) from the core of my heart for providing me inspiration for this endeavour and enabled me to complete this piece of work. This is entirely Allah’s favour and beneficence that He blessed me with the grace to render this service for the benefit of students, teachers and scientific community. In the end, I pray to Allah (SWT) to accept this humble effort of mine and enable the readers to get full benefit from this book. Dr. Muhammad Salim
URI: http://prr.hec.gov.pk/jspui/handle/123456789/9539
ISBN: 978-969-417-NIL-0
Appears in Collections:Textbooks.

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