Crop Production Technologies for Sustainable Use and Conservation

Physiological and Molecular Advances

Munir Ozturk, Khalid Rehman Hakeem, Muhammad Ashraf, Muhammad Sajid Aqeel Ahmad, Munir Ozturk, Khalid Rehman Hakeem, Muhammad Ashraf, Muhammad Sajid Aqeel Ahmad

• Publisher: Apple Academic Press
• Year: 2019
• ISBN:
  9780429891731
• Edition: 1
• Topic: Biowissenschaften
• Subtopic: Wissenschaft Allgemein

Crop Production Technologies for Sustainable Use and Conservation: Physiological and Molecular Advances presents an abundance of research on important and new production technologies for the successful sustainable production of major crops. The volume covers most of the major crops used the production of food, sugar, and commercial fiber. With the focus on sustainability and conservation issues in crop production, the chapters present molecular and physiological research and innovations for increasing yield, quality, and safety while also taking into considering increasing demand, diminishing water and land resources, and the agricultural consequences of climate change on crop production.

The major crops discussed include wheat, mungbean, cotton, jute, sugarcane, eggplant, Solanum (such as potatoes and tomatoes), peppers, okra, fruits such as apples and pears, and more. The chapters report on new developments and research on production techniques related to various fertilizers, biosystematics and molecular biology of various crops, and building resistance to climatic change, including drought tolerance, salinity stresses, and more.

CHAPTER 1

PLANT GENETIC RESOURCES OF MAJOR AND MINOR CROPS: ORIGIN, SUSTAINABLE USE, AND CONSERVATION

MANSOOR HAMEED¹, MUHAMMAD SAJID AQEEL AHMAD¹, MUHAMMAD ASHRAF², MÜNIR ÖZTÜRK³, and SANA FATIMA¹

¹Department of Botany, University of Agriculture, Faisalabad (38040), Pakistan, E-mail: [email protected]

²Institute of Molecular Biology and Biotechnology, The University of Lahore, Lahore, Pakistan

³Botany Department and Center for Environmental Studies, Ege University Bornova, Izmir, Turkey

ABSTRACT

Plant genetic resources contribute to approximately 60% of human food and other socio-economic needs. However, the present situation of plant genetic resources is alarming because a number of traditional crops and varieties are out of cultivation and human dependence on crop plants is restricted to only a few cereals and legume cultivars. This situation is worst in some cases where germplasm of traditionally cultivated crops is being depleted or has been permanently lost. In this situation, exploration, and conservation of not only the genetic resources of all major and minor crops, but also of ancestral and wild and weedy species is crucial. The importance and use of genetic resources in crop improvement programs and strategies for their conservation have been discussed in detail in this chapter.

1.1 INTRODUCTION

Plant genetic resources (germplasm resources or gene pools) are the complete generative/vegetative or reproductive materials within or among the species, which are used mainly for economic, scientific or social purposes (Hammer et al., 1999; Frankel and Hawkes, 2011; Pautasso, 2012). Many fields of plant sciences are benefited significantly from genetic resources, e.g., ecology, and evolution, physiology, and biochemistry, cytogenetics, and molecular biology, agronomy, pathology, breeding, and many others. Conventional breeding programmes and genetic engineering largely depend upon the genetic resources (i.e., genetic diversity), not only for improving yield and nutritive quality (Evenson et al., 1998; Frankel and Hawkes, 2011), but also for improving resistance or adaptation potential against a variety of biotic and abiotic stresses (Cherry et al., 2000; Fritsche-Neto and Borém, 2012).

Genetic diversity of crop plants has been disappearing rapidly because of modern agricultural practices like preference of monocultures of high-yielding varieties and GM plants, and loss of primitive cultivars and land-races, mainly due to habitat conversion (Wolfenbarger and Phifer, 2000; Hyten et al., 2006; Schmidt and Wei, 2006: Kovach and McCouch, 2008). However, a large reservoir of genetic diversity still exists in the form of landraces, farmer’s varieties and even wild relatives of crop plants with a tremendous amount of useful genetic variation (Harlan, 1975; Naeem et al., 2012). These gene pools are critically important in breeding for adaptation to environmental factors, resistance to biotic and abiotic stresses, or better nutritive value in crop plants, as these cannot be developed by artificial means (Ashraf and Akram, 2009; Ahmad et al., 2012). However, to a limited extent, these can be created using mutation breeding or genetic engineering techniques (Fridman and Zamir, 2012; Perez-de-Castro et al., 2012).

Plant genetic resources or gene pools can be categorized into three major groups on the basis of their degree of sexual compatibility: i) primary gene pool includes all crop plants and those species that can produce fertile hybrids, ii) secondary gene pool with plant species that contains certain barriers against crossing, and iii) tertiary gene pool with plant species that can be crossed only with the help of modern techniques (Gepts, 2000). However, (Gladis and Hammer, 2002) recognized the fourth gene pool, which includes synthetic strains that are developed through transgenic technologies and that do not occur in nature.

Evolution of species and domestication is largely dependent on genetic diversity in plants. Farmers have used this genetic diversity in developing promising and high-yielding crop species since the inception of agriculture (Konig et al., 2004; Vaughan et al., 2007). Genetic variability can play a fundamental role in crop improvement and development of new varieties, as it provides basic material for breeding and genetic engineering, extremely helpful for desired traits in crop plants according to the human need (Konig et al., 2004; Vaughan et al., 2007). Today, only 12 species (mainly wheat, rice, maize, and potatoes) contribute to 70% of the total food supply of the world (Wilson, 1992). Food security in the future may be ensured through the exploitation of all available genetic resources, i.e., not only the consumption of traditional crops but also the utilization of other wild, minor, and under-utilized crops (Brussaard et al., 2010).

1.2 ANCESTORS OF CROP PLANTS

During the evolutionary history, crops have enlarged their geographical ranges, and therefore extended over large areas. Species continued evolving and picking up the germplasm from related species since the domestication started, and consequently further extended their range. Because of this, there was more complexity in the genetic makeup of the species. This is an important process, in which sometimes the ancestors of a species are completely absorbed and may become extinct, because the ancestors compete out by their hybrids. Its good example is maize, the traditional varieties of which are out of cultivation due to the extensive development of hybrids (Blixt, 1994; Glaszmann et al., 2010b).

Majority of the domesticated plants can still produce fertile hybrids by crossing them with their wild ancestors. In some crops like maize and date palm, such crossing is indispensable for maintaining genetic diversity (Gross and Olsen, 2010). It was predicted that the major cereal crops were wild ancestors at one time, and therefore in most cases, the domesticated plants and their wild ancestors are genetically closely related (Vaughan et al., 2008; Abbo et al., 2012).

Improvement in crop production and food security essentially depends on conservation of these ancestral species (Hawkes et al., 2000). Currently, wild ancestors and wild relatives of crop plants are under serious threat of becoming extinct, which are obligatory for maintaining useful genetic diversity in agricultural crops, as well as in natural species (Maxted et al., 2008; Maxted et al., 2011). Degradation and destruction of natural environments (habitat loss), conversion of natural habitats for other uses, loss of many fruits and industrial crop species (deforestation), wild relatives of cereal crops by overgrazing and desertification, and industrialization of agriculture radically reduced the occurrence of ancestral species of crop plants (Maxted et al., 1997; Heywood and Dulloo, 2006).

Bread wheat (Triticum aestivum L.) was the result of natural hybridization between wild species of einkorn wheat (Triticum urartu L.) and goat grass (Aegilops speltoides L.). The later is now extinct, which gave rise to emmer wheat (T. diccocoides). This species then went hybridization with another species of goat grass (Aegilops tauschii) to form T. aestivum (Eckardt, 2010; Peng et al., 2011).

Similarly, turnip (Brassica rapa) is a close relative of B. oleracea complex, which includes broccoli, Brussels sprout, and kale. Wild species of these species are still found on sea-cliffs and in semi-arid and arid regions. During evolutionary history, species with proliferate masses, longer flowering period and enlarged axillary buds have resulted. Brassica napus were resulted from the natural cross between B. oleracea and B. rapa (Prakash et al., 2010; Anjum et al., 2012).

Wild potatoes e.g., Solanum jamesii, Solanum berthaultii, etc. are bitter in taste due to the presence of many toxic alkaloids (Caruso et al., 2011). Ancestral species of potato (Solanum tuberosum L.) is not known, but species with low alkaloids like S. brevicaule, S. canasense, S. leptophyes, and S. sparsipilum may contribute a lot to the domestication of modern potato (Brown, 2011). However, more likely the ancient cultivated form S. tuberosum ssp. andigena is the ancestral species. Evolution has resulted in the development of a genotype with fewer flowers, shorter stolons and large nomogenous tubers with different day-length requirements (Hawkes, 1990; Cooper et al., 2001).

Lycopersicon esculentum and L. pimpinellifolium along with nine other closely related species are the ancestral species of cultivated tomato (L. esculentum), which are widespread in Central America. Disease resistance was the main focus in the domestication of modern cultivars (Jenkins, 1948; Breto et al., 1993). Ancestral species of the cultivated pea (Pisum sativum) is the wild relative of P. elatius, however, P. fulvum equally contributed to the domestication of modern pea cultivars. Non-shattering pods, large, and thin-coated seeds, and erect habit of plants were the main focus of domestication (Cupic et al., 2009; Jing et al., 2010; Jing et al., 2012).

Domestication of cultivated rice (Oryza sativa) is little controversial. Previously it was believed that rice was domesticated from wild Asian progenitors, O. nivara and O. rufipogon (Ge et al., 1999). More recently, it was investigated that introgression was the key factor controlling rice domestication. Critical domestication alleles e.g., (non-shattering) were fixed during the evolutionary history, and thereafter introgression frequently occur between early cultivar and its wild progenitors, and as a result, modern cultivars such as indica and japonica derived as hybrids (Sang and Ge, 2007).

It is now widely accepted that all pre-Columbian maize landraces arose from a specific teosinte (Zea mays ssp. Parviglumis), about 9000 years ago through a single domestication event in southern Mexico (Matsuoka, 2005). Teosinte can produce fertile hybrids with maize and other related species, such as Tripsacum, all geographically restricted to Mexico and Guatemala (Wllkes, 1977; de Wet et al., 1981; De Wet, 2009).

Ancestral species or wild relatives of the crop plants are now considered as an increasingly important resource for improving production and biotic/abiotic stress tolerance of the agricultural crops, and therefore, vital for ensuring food security for the future generations. These species contain a number of useful genes, which can be effectively incorporated in modern crops. Such practices have been successfully done in the past, and there are several examples of useful gene transfer from wild and ancestral species into major crops including cereals, legumes, oilseed, fiber, and fodder crops.

1.3 DOMESTICATION OF CROP PLANTS

Crop plants were domesticated when people started cultivation and management of the wild ancestral species. Historical evidence indicates that crop plants should have been domesticated between 3,000 to 10,000 years ago, i.e., soon after the end of the Pleistocene era. In ...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Contributors
• Abbreviations
• Preface
• 1. Plant Genetic Resources of Major and Minor Crops: Origin, Sustainable Use, and Conservation
• 2. Wheat Production Technology: A Preamble to Food Security in Pakistan
• 3. Capsaicin Production in Cell Suspension Cultures of Capsicum annuum L.
• 4. Drought-Induced Changes in Growth, Photosynthesis, and Yield Traits in Mungbean: Role of Potassium and Sulfur Nutrition
• 5. Cotton, White Gold of Pakistan: An Efficient Technique for Bumper Crop Production
• 6. Corchorus Species: Jute: An Overutilized Crop
• 7. Recent Developments in the Biosystematics and Molecular Biology of Sugarcane
• 8. Comparative Study of Three Different Fertilizers on Yield and Quality of Capsicum
• 9. Comparative Study of Three Different Fertilizers on Yield and Quality of Solanum
• 10. Biology and Biotechnological Advances in Apple: Current and Future Scenario
• 11. Pears (Pyrus) of Northern Pakistan
• 12. Enhancing the Drought Tolerance in Eggplant by Exogenous Application of Osmolytes in Water-Deficit Environments
• 13. Enhancing Morpho-Physiological Responses and Yield Potential in Okra (Abelmoschus esculentus L. Moench) under Salinity Stress
• 14. Sugar Beet: An Overutilized Ancient Crop
• 15. An Overutilized Industrial Crop: Tobacco: Nicotiana tabacum L. Case Study from Turkey
• 16. Wild Relatives and Their Role in Building Resistance in Bread Wheat: At a Glance
• 17. Structural and Functional Genomics of Potato (Solanum tuberosum)
• Index