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Crop wild relatives (CWRs) are the potential source of novel traits and genetic variation in food crops with narrow genetic base. CWRs include immediate progenitor of crop species and other species of plants which are closer to them in near evolutionary history. CWRs are the sources of novel alleles for several important traits of nutritional and agronomical importance. Introgression of such valuable alleles into working germplasm of a breeding programme depends on sexual compatibility of CWRs with crop species in cultivation. Scientific techniques have been developed to overcome compatibility among them up to certain extent. Simultaneous discovery and transfer of useful alleles into cultivable background have been demonstrated in certain crop species with success. Utilisation of completely incompatible species has been made easier by methods such as somatic hybridization. With ever increasing innovations in the field of genomics science, hope to harness the potential of CWR has grown up to new heights. CWRs have been successfully utilised to enhance quality of crop produce in wheat, barley, tomato, etc., and also have been exploited to create new species such as triticale as well as to understand crop evolutionary history in different crops. CWRs are also a good source of cytoplasmic male sterility which makes them amenable to boost commercial breeding programs. Many CWRs are natural source of abiotic and biotic stresses. Importance of CWR has become more relevant in the era where threat of climate change is apparent and mitigation approaches such as transgenics are being increasingly criticised on many fronts. In the era facing the challenges of genetic erosion of diversity and extinction of species, systematic collection, conservation, and characterization of available genetic diversity of CWRs is immensely important. Prebreeding of wild germplasm is among other challenges for successful utilization of such highly potential genetic resources for enhancing crop breeding efforts.

Crop improvement technologies developed at various research institutes of ICAR and state agricultural universities need to be practically demonstrated at the beneficiary farmer's field. To attain this objective the concept of Krishi Vigyan Kendras (Farm Science Centre) came into existence. After the preliminary trials of proven technologies at the farm science centre level, large trials called the Front Line Demonstrations are conducted at farmer's field to check the suitability and reproducibility of the technology at micro environment level. In addition to the OFTs and FLDs, training is also given tofarmers, rural youth and extension functionaries from time to time to update then regarding the latest technologies developed for crop improvement.

Plant kingdom, the base for every ecological pyramid, serves as a key source for food and evolution. Individualisation and analysis of genetic diversity and relatedness between or within different species, genera and population are the central task for many disciplines of biological science. Till recently, only the morphological traits/markers have been extensively used for this purpose. However, these morphological markers are often influenced by environment, which require special experimental designs to distinguish genotypic and phenotypic variation in a population. Later, the developments in biochemistry and molecular biology complemented many markers like protein, isozyme and DNA markers, which enable the breeders to overcome the limitations faced in the use of morphological markers. They show co-dominance (with exception of Random Amplified Polymorphic DNA (RAPD), mostly a dominant marker) so that all the genotypes can be classified, a large number of samples can be analysed, require only a limited quantity of plant tissue for analysing, thus eliminating the need for raising a large population in the field and one need not wait for the maturity of the plant. All living organisms are made up of cells that are programmed by genetic material called DNA. This molecule is made up of a long chain of nitrogen-containing bases (there are four different bases: adenine (A), cytosine (C), guanine (G) and thymine (T). Only a small fraction of the DNA sequence typically makes up genes, i.e., that code for protein, while the remaining and major share of the DNA represents non-coding sequences, the role of which is not yet clearly understood. The genetic material is organised into sets of chromosomes (e.g., five pairs in Arabidopsis thaliana; 30 pairs in Bos taurus (cow), and the entire set is called the genome. In a diploid individual (i.e., where chromosomes are organised in pairs), there are two alleles of every gene, one from each parent. Marker-assisted selection (MAS) is the breeding strategy in which selection for a gene is based on molecular markers closely linked to the gene of interest, rather than gene itself and the markers are used to monitor the incorporation of desirable allele from the donor source. Molecular markers should not be considered as normal genes as they usually do not have any biological effect. Instead, they can be thought of as constant landmarks in the genome. They are identifiable DNA sequences, found at specific locations of the genome and transmitted by the standard laws of inheritance from one generation to the next. They rely on a DNA assay in contrast to morphological markers that are based on visible traits, and biochemical markers that are based on proteins produced by genes. Different kinds of molecular markers exist, such as restriction fragment length polymorphisms, RAPDs markers, amplified fragment length polymorphisms, microsatellites and single-nucleotide polymorphisms (SNPs). Thus, MAS is the breeding strategy in which selection for a gene is based on molecular markers closely linked to the gene of interest, rather than gene itself and the markers are used to monitor the incorporation of desirable allele from the donor source.

Pre-breeding refers to all activities designed to identify desirable characteristics and/or genes from unadapted (exotic or semi-exotic) materials, including those that, although adapted, have been subjected to any kind of selection for improvement. It is an essential part of germplasm diversification strategies. Pre-breeding is the most promising alternative to link genetic resources and breeding programmes. As pre-breeding is being carried out, the resulting materials are expected to have merit to be included in ordinary breeding programmes. There are at least three distinct uses of genetic enhancement. The first is to prevent genetic uniformity and consequent genetic vulnerability. Only recently has pre-breeding-genetic enhancement-become a necessary, frequent and planned part of all plant breeding activities, an essential part of germplasm diversification strategies. Genetic enhancement has a second important purpose that of raising yield levels to new heights. This goal is more often hoped for than achieved, but it is true that most breakthrough cultivars have highly diverse parentage. The semi-dwarf wheat, the high yield dwarf rice, the first US hybrid sorghums and even the first US Corn Belt dent maize cultivars are examples. In each case, extensive pre-breeding preceded development of the breakthrough, high-yield cultivars. The pre-breeding was used to adapt diverse kinds of germplasm to new genetic backgrounds and new geographic locales. Genetic enhancement is used to bring in new quality traits not found in local cultivars. New levels of protein percentage in wheat or unusual starch properties in maize are examples.

Arbuscular mycorrhiza (AM) is possibly the most prevalent constituent of global symbiosis and is created by 70–90% of land plant species with fungi that belong to a monophyletic phylum, the Glomeromycota. The initiation of the AM fungal root colonisation begins with hyphae growing towards the plant root and extensively around it, where they subsequently attach to the root surface. This relationship results in an improved acquisition of nutrients (e.g., phosphate and nitrates) from the soil by the plant partners and, in exchange, allows the Arbuscular Mycorrhizal Fungi (AMF) to obtain the photosynthetically fixed carbon sources (e.g., sugars) necessary for their survival and propagation. AM symbiosis is very common as the fungi involved can colonise a vast taxonomic range of both herbaceous and woody plants, which are geographically cosmopolitan and ubiquitous, occurring over a broad ecological range in plants growing in the arctic, temperate and tropical regions. In this review, the development, host range, functioning of AM and its benefits for sustainable farming will be discussed.

Heterosis for yield components and yield per plant was studied using 7x7 half diallel cross between bacterial wilt-resistant/tolerant genotypes and high-yielding varieties. The heterosis over better parent (BP) was up to the extent of -38.14%, 42.04%, 36.14, -5.70%, -5.65%, 26.32%, 63.44%, 4.83%, 16.50%, 38.88%, 62.70% and 45.89% was recorded for plant height, number of primary branches per plant, number of secondary branches per plant, days to 50% flowering, days to maturity, fruit set, fruit length, fruit width, number of locules per fruit, number of fruits per plant, fruit weight and fruit yield per plant, respectively. The extent of heterosis was not so high as we are also looking for resistant to the bacterial wilt disease. The crosses showing heterosis for fruit yield per plant were not heterotic for all the characters under study. The heterosis for yield was generally accompanied by heterosis for yield components. Five promising crosses viz., Arka Ahuti x LO-5973, Arka Vikas x TWC-4, Arka Ahuti x TWC-4, BRH-2 x LO-5973 and CAU-TS-9 x LO-5973 were identified for developing high-yielding F1 hybrids/varieties of tomato with many desirable traits.