Preface

Chapter 7 **Breeding to Improve Symbiotic Effectiveness of Legumes 167**

Chapter 8 **Opium Poppy: Genetic Upgradation Through Intervention of**

Máira Milani and Márcia Barreto de Medeiros Nóbrega

**by Knowledge Sharing. The Portuguese Experience 255** Maria Carlota Vaz Patto, Pedro Manuel Mendes-Moreira, Mara Lisa Alves, Elsa Mecha, Carla Brites, Maria do Rosário Bronze and Silas

Chapter 10 **Participatory Plant Quality Breeding: An Ancient Art Revisited**

Brij Kishore Mishra, Anu Rastogi, Ameena Siddiqui, Mrinalini

**Plant Breeding Techniques 209**

Tikhonovich

**VI** Contents

Sudhir Shukla

Chapter 9 **Castor Breeding 239**

Pego

Vladimir A. Zhukov, Oksana Y. Shtark, Alexey Y. Borisov and Igor A.

Srivastava, Nidhi Verma, Rawli Pandey, Naresh Chandra Sharma and

Breeding of crop plants to make them more adapted to human agricultural systems has been on-going during domestication the last 10 000 years. However, only recently with the inven‐ tion of the Mendelian principles of genetics and the subsequent development of quantitative genetics during the twentieth century has such genetic crop improvement become based on a general theory. During the last 50 years plant breeding has entered a molecular era based on molecular tools to analyse DNA, RNA and proteins and associate such molecular results with plant phenotype. These marker trait associations develop fast to enable more efficient breeding. However, they still leave a major part of breeding to be performed through selec‐ tion of phenotypes using quantitative genetic tools. The ten chapters of the book illustrate this development.

#### **Genomics and Marker Assisted Breeding**

Future plant breeding will move much beyond the conventional genetic barriers consisting of the species limits. Different crops derived from different species are the result of evolu‐ tion, during the past thousands of years to a certain extent driven by humans. Only recently have we come to understand that our crop plants have arisen through genetic bottle necks since only a minor part of globally existing genetic diversity has been searched for agricul‐ turally useful genes. Since crops are the result of evolution they are genetically related and well-functioning genes from one crop may be useful also in other related crops exchanged through species hybridisation, or in the case of distantly related or different types of organ‐ isms through genetic engineering.

Much understanding of relations between crop plants has been obtained through in situ hy‐ bridization techniques described in detail by Brammer et al. (Chapter 1) for the triticae fami‐ ly, which beautifully pictures the principles of synteny; the fact that chromosomal arrangements of genes are partially maintained over millions of years of evolution. Com‐ bined with the rapid development of new techniques of molecular genetic markers (Li et al. Chapter 2), which will efficiently detect desired alleles of a gene during breeding operations, our window of breeding, still mainly within species, may open widely during the next fu‐ ture to more frequently exploit new genes across traditional species barriers. It may also open up for general use of the still existing widely diversified wild crop relatives.

Such use of molecular markers for marker assisted breeding described by Jiang (Chapter 3) is based on the principles of genetic linkage, so that markers surrounding or inside a gene affecting a breeding trait, tend to be inherited together with the trait and therefore complete‐ ly or partially can reveal the phenotype of the plant. With further development in the num‐ ber of such molecular markers, which can be analysed for a lower prize, the use of marker assisted breeding can be expected to move from breeding of mainly simply inherited to more complex traits, comprising large numbers of quantitative trait loci (QTL) affecting dif‐ ferent important breeding traits (genomic selection).

Until now the development of marker assisted breeding for semi-quantitative traits have de‐ veloped most for the breeding of more horizontal types of disease resistance, like resistance to blackleg of rapeseed (Raman et al, Chapter 4) and horizontal resistance to several com‐ mon bean diseases ( Tryphone et al, Chapter 5). These chapters demonstrate well the process of dissection of conventionally quantitative traits of disease resistance into chromosomal sections (QTL) covered with genetic markers. The result is a limited number of genes or QTL with known chromosomal locations, different alleles with different effects as well names for each gene. This makes possible the planning of breeding operations to backcross or stack (pyramide) such resistance to an extent previously not possible with conventional breeding. In particular these developments in the breeding of more complex types of disease resistance may find great use to breed cultivars with more durable disease resistance than when more simply inherited sources of resistance are used.

#### **Crop Breeding for Complex Phenotypes**

Limitation in water supply is a major constraint to food production world-wide and it is expected to intensify with future climate change. Better genetic tolerance to such drought conditions, which should result in improved exploitation of available water, however, is a highly complex trait controlled by different genes for different plant development stages and with severe interactions between genes of the crop and its growing environment (Sha‐ shidhar et al, Chapter 6). This results in rather long term breeding programs the success of which highly depends on good choice of breeding material, target region of cultivation and multisite selection environment.

Most land plants have developed various types of symbiosis with microorganisms, which may have major impacts on the plant's nutrient supply. These central biological phenomena are mostly known fromlegume-rhizobium interactions (Zhukov et al, Chapter 7), but they are still used only to a limited extend to breed e.g. legume crops with higher nitrogen fixa‐ tion rates. Recent molecular developments and improved understanding of the complex plant microbe interactions in such symbiosis may enable future systematic breeding for le‐ gume crops with higher nitrogen fixation to reduce the need of nitrogen fertilizer in future agriculture. Furthermore, better understanding of the principles of beneficial plant microbe interactions in the legume system may enable the breeding of other crops for improved ben‐ eficial symbiosis with microorganisms.

The chapter by Mishra et al (Chapter 8) on opium poppy is a good example of the complex breeding of an important medicinal plant. Desire of high contents of alkaloids combined with good adaptation to cultivation methods turns improvement of the crop into highly complex breeding programs, which may be simplified in the future through better under‐ standing of the regulation of synthetic pathways.

Another example of improvement of an industrially important crop to a large extent pro‐ duced by small growers on marginal land is the breeding of Castor (Ricinus communis) (Mi‐ lani et al, Chapter 9). The castor oil produced from the plants feeds several different types of chemical industry, and breeding for high oil content combined with adaptation to cultiva‐ tion system leads to complex breeding programs, where choice of plant material, targeted growers and type of cultivar is essential for success.

assisted breeding can be expected to move from breeding of mainly simply inherited to more complex traits, comprising large numbers of quantitative trait loci (QTL) affecting dif‐

Until now the development of marker assisted breeding for semi-quantitative traits have de‐ veloped most for the breeding of more horizontal types of disease resistance, like resistance to blackleg of rapeseed (Raman et al, Chapter 4) and horizontal resistance to several com‐ mon bean diseases ( Tryphone et al, Chapter 5). These chapters demonstrate well the process of dissection of conventionally quantitative traits of disease resistance into chromosomal sections (QTL) covered with genetic markers. The result is a limited number of genes or QTL with known chromosomal locations, different alleles with different effects as well names for each gene. This makes possible the planning of breeding operations to backcross or stack (pyramide) such resistance to an extent previously not possible with conventional breeding. In particular these developments in the breeding of more complex types of disease resistance may find great use to breed cultivars with more durable disease resistance than

Limitation in water supply is a major constraint to food production world-wide and it is expected to intensify with future climate change. Better genetic tolerance to such drought conditions, which should result in improved exploitation of available water, however, is a highly complex trait controlled by different genes for different plant development stages and with severe interactions between genes of the crop and its growing environment (Sha‐ shidhar et al, Chapter 6). This results in rather long term breeding programs the success of which highly depends on good choice of breeding material, target region of cultivation and

Most land plants have developed various types of symbiosis with microorganisms, which may have major impacts on the plant's nutrient supply. These central biological phenomena are mostly known fromlegume-rhizobium interactions (Zhukov et al, Chapter 7), but they are still used only to a limited extend to breed e.g. legume crops with higher nitrogen fixa‐ tion rates. Recent molecular developments and improved understanding of the complex plant microbe interactions in such symbiosis may enable future systematic breeding for le‐ gume crops with higher nitrogen fixation to reduce the need of nitrogen fertilizer in future agriculture. Furthermore, better understanding of the principles of beneficial plant microbe interactions in the legume system may enable the breeding of other crops for improved ben‐

The chapter by Mishra et al (Chapter 8) on opium poppy is a good example of the complex breeding of an important medicinal plant. Desire of high contents of alkaloids combined with good adaptation to cultivation methods turns improvement of the crop into highly complex breeding programs, which may be simplified in the future through better under‐

Another example of improvement of an industrially important crop to a large extent pro‐ duced by small growers on marginal land is the breeding of Castor (Ricinus communis) (Mi‐ lani et al, Chapter 9). The castor oil produced from the plants feeds several different types of chemical industry, and breeding for high oil content combined with adaptation to cultiva‐

ferent important breeding traits (genomic selection).

VIII Preface

when more simply inherited sources of resistance are used.

**Crop Breeding for Complex Phenotypes**

multisite selection environment.

eficial symbiosis with microorganisms.

standing of the regulation of synthetic pathways.

Finally the use of participatory plant breeding, where farmers growing a crop in an area are involved in breeding and maintenance of their plant material (Vaz Patto et al, Chapter 10) illustrates the potential of shared ownership among farmers for a high quality local type of maize. Particularly in times with strong concentration of breeding activities into relatively few breeding companies enforcing intellectual property rights on cultivated material this ex‐ ample from Portugal stands out as a means to preserve a special local production.

**Sven Bode Andersen, Professor Phd**

Faculty of Science, University of Copenhagen, Danmark

**Genomics and Marker Assisted Breeding**
