Arvind H. Hirani

Homoeologous GSL-ELONG gene replacement for manipulation of aliphatic glucosinolates in Brassica rapa L. by marker assisted selection.

Aliphatic glucosinolates are the predominant sulfur-rich plant secondary metabolites in economically important Brassica crops. Glucosinolates and their hydrolysis products are involved in plant–microbe, plant–insect, plant–animal, and plant–human interactions. It is, therefore, important to manipulate glucosinolate profiles and contents in Brassica species. In this study, aliphatic glucosinolates were genetically manipulated through homoeologous recombination in backcross lines followed by marker assisted selection in B. rapa. A resynthesized B. napus line, from a cross between B. rapa and B. oleracea, was backcrossed with Chinese cabbage doubled haploid line, RI16. Marker assisted selection for non-functional gene was performed in each backcross generations. Advanced backcross progenies (BC3F2) were developed to identify homoeologous gene replacement and/or introgression. Reduction in 5C aliphatic glucosinolates (gluconapoleiferin, glucoalyssin, and glucobrassicanapin) was observed in BC3F2 progenies of the recurrent parent that carried the GSL-ELONG- gene. The GSL-ELONG- positive backcross progenies were also screened by the A-genome and BraGSL-ELONG gene specific marker, which linked with 5C aliphatic glucosinolates. The A-genome specific marker was absent in the plants of advanced backcross progenies which showed reduction in 5C aliphatic glucosinolates. The results suggest that the functional allele had been replaced by the non-functional GSL-ELONG- allele from B. oleracea. Some advanced backcross progenies (BC3F2) positive for the GSL-ELONG- allele and the A-genome specific SCAR marker BraMAM1-1 did not show reduction in 5C aliphatic glucosinolates, suggesting that GSL-ELONG- allele is recessive. Replacement of the functional locus in the A-genome by non-functional counterpart in the C-genome reduced the content of 5C aliphatic glucosinolates in B. rapa seeds with 20 μmol/g.

Molecular Genetics of Glucosinolate Biosynthesis in Brassicas: Genetic Manipulation and Application Aspects

Glucosinolates are sulphur containing secondary metabolites biosynthesized by many plant species in the order Brassicales. Physical tissue or cell injury leads to the breakdown of glucosinolates through the hydrolytic action of the enzyme myrosinase, resulting in the production of compounds including isothiocynates, thiocyanates and nitriles. Derivative compounds of glucosinolates have a wide range of biological functions including anticarcinogenic properties in humans, anti-nutritional effects of seed meal in animals, insect pest repellent and fungal disease suppression (Mithen et al., 2000; Brader et al., 2006). Glucosinolates play important role in the nutritional qualities of Brassica products. Brassica products are consumed as oil, meal and as vegetables. Rapeseed (B. napus, B. juncea and B. rapa) is a source of oil and has a protein-rich seed meal. High glucosinolates in the seed meal pose health risks to livestock (Fenwick et al., 1983; Griffiths et al., 1998). Consequently, plant breeders have nearly eliminated erucic acid from the seed oil and have dramatically reduced the level of seed glucosinolates (>100 μmole/g seed to <30 μmole/g seed) via conventional breeding, allowing the nutritious seed meal to be used as an animal feed supplement. There is, however, a significant residual content of glucosinolates in rapeseed/canola seed meal (over 10 μmole/g seed) and further reduction of the total glucosinolate content would be nutritionally beneficial (McVetty et al., 2009). Therefore, to produce healthy seed meal from rapeseed, it is important to genetically manipulate glucosinolate content. Brassica vegetables (B. rapa and B. oleracea) are highly regarded for their nutritional qualities, they are a good source of vitamin A and C, dietary soluble fibres, folic acid, essential micro nutrients and low in calories, fat and health beneficial glucosinolates such as glucoraphanin and sulforaphane. Breeding objectives for these Brassica crops include the enhancement of beneficial glucosinolates and reduction of others. It is, therefore, important to understand the genetic, biosynthetic, transportation and accumulation mechanisms for glucosinolates in Brassica species.

Molecular Mechanisms Controlling Dormancy and Germination in Barley

Barley (Hordeum vulgare L.) is amongst the oldest crops within cereals. Archaeological remains of this crop have been discovered at different locations in the Fertile Crescent (Zohary & Hopf, 1993) indicating that barley is being cultivated since 8,000 BC. The wild relatives of barley were recognized as Hordeum spontaneum C. Koch. However, in the recent literature of taxonomy, H. spontaneum C. Koch, H. vulgare L., as well as H. agriocrithon Aberg, are believed to be the subspecies of H. vulgare (Bothmer & Jacobsen, 1985). Studies with molecular markers have confirmed that barley was brought into cultivation in the Isreal-Jordan area but barley diversification occurred in Indo-Himalayan regions (Badr et al., 2000).

Chapter 7 – Modeling for Agricultural Sustainability: A Review

Modeling in agriculture is an important tool to sustain productivity for food and feed security, particularly under fluctuating climatic conditions. Innovative crop management practices and sustainability in agriculture could be possible through advance modeling at the levels of soil, crop canopy, and their interaction. Modeling studies need to be carried out for soil processes, crop management, and long-term crop productivity predictions based on current or predicted climatic changes. This review focuses on several important models that are applicable in soil–water dynamics, crop productivity, and impact of resources on productivity. The data of research experiments are compared with predicted data for known models in different geographical locations for numerous production parameters that are discussed in detail regarding the validity and reliability measures of the respective models. Various models are also compared and discussed with respect to their prediction accuracy and reliability.

Identification of common QTL for resistance to Sclerotinia sclerotiorum in three doubled haploid populations of Brassica napus (L.)

Sclerotinia stem rot (SR) is one of the most devastating diseases of canola/rapeseed. Quantitative trait loci (QTL) analyses were carried out to identify loci responsible for resistance to SR in three doubled haploid DH populations (H1, H2 and H3). Petiole inoculation technique PIT was used to evaluate the all populations for resistance to SR. Genetic maps were developed using sequence related amplified polymorphism SRAP and simple sequence repeat SSR markers. Genetic maps of the H1 and H2 populations were developed using 508 and 478 markers, respectively. Previously published genetic map of the H3 population was also used in this study. The QTL analysis was carried out for each replicate separately as well as on the average of all the replicates. The numbers of identified QTL in each analysis varied from four to six in the H1 population, three to six in the H2 population and two to six in the H3 population. A number of common QTL were identified between the replicates of each population. Two common QTL were identified on linkage group A7 and C6 between the H1 and H3 populations and one QTL on A9 between the H2 and H3 populations. We are the first to report, identification of common QTL between different populations of Brassica napus.

Transferring clubroot resistance from Chinese cabbage (Brassica rapa) to canola (B. napus)

Abstract Clubroot, caused by Plasmodiophora brassicae, is one of the most important diseases of Brassica species worldwide, including vegetable and oilseed crops. A dominant clubroot resistance gene from B. rapa (Chinese cabbage) was previously fine mapped and molecular markers were developed in Chinese cabbage that could be used for marker-assisted selection (MAS) in other Brassica crops. To transfer this clubroot resistance gene to B. napus (canola), an interspecific hybridization was made between B. napus (canola) and B. rapa (Chinese cabbage). Subsequently, the F1 was backcrossed to the canola recurrent parent for three generations to produce BC1, BC2 and BC3 progenies. Using these populations, simple sequence repeat (SSR) markers flanking the clubroot resistance gene were used to perform MAS in canola. These molecular markers were then evaluated in 13 different canola and rapeseed quality genotypes in B. napus and B. rapa. These markers exhibited high reliability in identifying clubroot resistance in this diverse set of Brassica genotypes. Clubroot resistance also co-segregated with the SSR markers flanking the clubroot resistance gene in the BC3 and BC3S1. The segregation ratio of resistant and susceptible individuals in the BC3 supported the expected 1:1 ratio for the segregation of a single Mendelian gene. BC3S1 families with homozygous clubroot resistance were developed during this process, and should be valuable sources of clubroot resistance in B. napus breeding activities.

A Review on First- and Second-Generation Biofuel Productions

Renewable energy resources are in great urge to reduce dependability on fossil fuels as well as to minimize greenhouse gas emission. Since more than a decade, biofuel industries especially bioethanol and biodiesel have been highly expanding in conjugation with agriculture crop production. First generation biofuel production is highly relied on the agriculture crops such as corn, sugarcane, sugar beets, soybean, and canola. Therefore, inherent competition between foods versus fuels remained debatable in the society from the last few years. Current technological advances in the research and development opened an avenue for next-generation biofuel production from different feedstock such as agriculture waste products, crop residues, and cellulosic biomass from high-yielding grass species. This review explains the current status of first-generation biofuel production and their challenges at net energy benefit as well as competition of feedstock for food and fuel production. This chapter also focuses on recent advances in research and development of the second-generation biofuel production from different feedstocks. Future direction of agriculture industries and energy industries has been discussed to feed the ever-increasing world population and to fuel the world’s highest energy demanding sector, transportation.

Perspective of Biofuel Production from Different Sources

Biofuel is an emerging agri-industry that has the potential to change the agricultural economics of both developed, as well as developing, and underdeveloped nations in the not so distant future. Biofuels are regularly replacing fossil fuels to generate power, heat, and chemicals. The extensive use of biofuels in the future for energy generation is of great interest since it has the potential to reduce the concentration of greenhouse gases in the atmosphere and could serve as an important step toward establishing energy independence and open new employment opportunities globally. It is therefore important to understand the different sources of biofuel productions for long-term and sustainable use depending upon the nature and energy dynamics of the regional demands for biofuel. This review investigates the sustainability of biofuel production from different sources and their role in energy generation.

Conservation of Global Wheat Biodiversity: Factors, Concerns and Approaches

Wheat is an important food crop in the world. It is also one of the top three global food crops produced after rice and maize that constitutes an immensely significant role with respect to global food security. Due to finite land resources that can be dedicated to agriculture global wheat production has been consistently dependent on genetic improvement of wheat germplasm across the world. Traditional plant breeding has been an important tool in increasing global food production by producing disease and stress resistant, high yielding and early maturing wheat varieties. However, it is necessary to have a stable and divergent pool of wheat genotypes grown under different environmental conditions and different land races of wheat as genetic feedstock for enhanced genetic improvements. Due to increased global human population, extensive anthropogenic pollution and damages to the vulnerable local ecosystems, existing genotypes and land races of wheat are under constant threat of becoming extinct. Hence it is absolutely necessary to conserve the global wheat biodiversity for securing the future of our food security. Recent progress and developments in technological applications including those in the realm of biotechnology have turned out into an essential tool that could be effectively and efficiently utilized for wheat biodiversity conservation. This short review is an attempt to investigate different factors and concerns jeopardizing global wheat biodiversity and pinpoints some potential approaches for its successful conservation.

Major Insects of Wheat: Biology and Mitigation Strategies

Wheat is one of the major cereal crops with annual global production over 600 MT from about 200 M hectares (FAO 2012). The cultivation of wheat started about 10,000 years ago as part of the Neolithic revolution which state a transition from hunting and gathering of food to settle agriculture. Earlier cultivated forms of wheat were diploid (einkorn) and tetraploid (emmer) with known initial origin of the south-eastern part of Turkey (Dubcovsky and Dvorak, 2007). Subsequent evolutionary adaptation and continuous research produced hexaploid bread wheat that is currently widely adapted in about 95% area of world wheat. Globally, all crop production practices are being highly challeged by biotic and abiotic stresses. Biotic stresses especially insect pests and dieseases causes devastating damage in terms of yield and quality. On average pests cause 20-37% yield losses woldwide which translating to approximately