**8. Future directions**

was closely linked with Fw at 19.7 cM [115]. In an another study, a set of 122 functional SSR markers have been developed using a genomic library enriched for GA/CT motifs for utiliza-

128 Fusarium - Plant Diseases, Pathogen Diversity, Genetic Diversity, Resistance and Molecular Markers

As lentil has a narrow genetic base an inter-varietal linkage maps were developed by utilizing diverge parents from the wild and cultivated species but these maps have low recombination rate and the map size is also small. QTLs responsible for many traits can be identifying by intra specific mapping population and desirable gene of interest can be tagged. First intra specific lentil map was developed by Ford et al. (2003) through RAPD and ISSR markers [117]. Bi-parental mapping populations derived from the most divergent parents are always better for developing recombinant inbred line and through that a dense mapping or fine mapping can be done from the population developed through the cross of resistant and susceptible parents. These maps are useful to identify genes and major QTLs responsible for the variation of the trait of interest. Gene cloning can help to characterize the function of the gene or QTLs responsible for the wilt and the knowledge of the genes cloned in lentil can facilitate the development of functional markers for the marker assisted selection. Resistant genes for different functions have cloned in lentil [118]. Using functional genomics approaches, genes expressing differentially in con-

Focusing towards the natural defense of host plant may reduce the impact of the pathogen on productivity. However, our poor knowledge about the molecular interaction between the crop and the pathogen limits support for breeding disease-resistant varieties. Due to the development of sequencing technologies, several genes coding transcription factors (TFs) and candidate defense genes (CDGs) from lentil are identified [112]. The full sequence of candidate defense genes like a β-1,3-glucanase (GLU1) (CV793598), a pathogenesis-relate (PR) protein from the Bet v I superfamily (AY792956), a disease resistance response protein 230 (DRR230-A) from pea (AJ308155), another disease resistance response protein (DRRG49-C) from pea (J03680), a pathogenesis-related 4 (PR4) type gene (DY396388) and a gene encoding an antimicrobial SNAKIN2 protein from tomato (HQ008860) are available in NCBI Genbank [112]. A partial sequence of translation elongation factor-1α (TEF-1α) (KR061303 and KR061304) from *Fusarium nygamai* infecting lentil were also deposited in Genbank [33]. These candidate genes and TFs should be further biologically characterized and can help us

Integration of two or more disease management option can reduce the impact of any disease affecting crops. The expected benefit in opting this strategy is improved and sustainable control of disease. The use of biocontrol agents in combination with chemical control can act as one of the strategies in controlling some soil-borne diseases. Therefore, some researchers have used the combination of *Bacillus megaterium* with carbendazim, which provided an effective control of Fusarium crown and root rot of tomato [119]. Similarly, the combination of soil amendments and biological control agents such as *Trichoderma* spp., have been shown to increase disease control and horticultural productivity [120]. Nowadays the use of organic

amendments to improve soil properties, plant health and yield has expanded [121].

tion in the lentil breeding program [116].

trasting lentil genotypes can be identified.

in decoding the defense pathways and pathogen recognition.

**7.7. Integrated management of Fusarium wilt of lentil**

Knowledge about the pathogen has improved since it was observed, but still few challenges remain. A region specific race of the pathogen is needed. Since there are potential differences in the reaction of lentil cultivars to different races of the pathogen, so information about the distribution of races will be of great importance for breeding programs and the development of resistant genotypes. Along with this, a standardized set of host differentials is required to correlate pathogenicity with DNA techniques. A robust screening techniques for resistant to the pathogen is also required. With the lack of host-pathogen interaction studies, management remains elusive and additional research is needed in this area. Marker assisted selection (MAS) offers great opportunity for improved efficiency and effectiveness in the selection of plant genotypes with a desired combination of traits. Through marker assisted selection, disease resistance can be evaluated in the absence of the disease and in early stages of plant development. Implementation of markers for routine use in lentil breeding programs is currently very limited, integration of the markers within the breeding program to ensure that cost effective utilization of the technology is achieved. Establishment of a tight linkage between a molecular marker and the chromosome allocation of the gene(s) governing the trait to be selected in a particular environment is required. The information from multiple populationspecific genetic maps can be integrated to produce high-density consensus structures utilizing the sequence-linked genetic markers which enables the identification of bridging loci between maps. This will further assist in the identification of more closely linked markers for Fusarium wilt resistance in lentil that can be effectively used in breeding and there is a need to develop and map more functional markers like EST-SSRs and SNPs on such maps to enhance their relevance in lentil genetics and breeding. The study based on SNP markers is still limited in lentil due to the lack of available sequence data. For effective variety development marker assisted selection is very imprint that requires much attention in lentil breeding program. Comparative genomics and synteny analyses with closely related legumes can play an important role in enhancing the knowledge of the lentil genome and can provide the genes and selectable markers for use in MAS. Transgenic and non-transgenic approaches including RNAi technology and virus-induced gene silencing (VIGS) can be explore to understand the molecular mechanisms of host resistance in lentil. Additional refined genetic materials are required in order to apply advanced genomic tools such as transcriptome profiling and map-based gene cloning of lentil. Germplasm with wilt resistance and drought tolerance are key areas of emphases since the later pre-dispose the crop to *Fusarium* infection. In addition to host plant resistance, integrated management of Fusarium wilt is very important to narrow the yield gap due to Fusarium wilt in many countries.

[9] Duran Y, Fratini R, Garcia P, De La Vega MP. An inter subspecific genetic map of Lens.

Fusarium Wilt: A Killer Disease of Lentil http://dx.doi.org/10.5772/intechopen.72508 131

[10] Quinn MA. Biological nitrogen fixation and soil health improvement. In: Erskine W, Muehlbauer FJ, Sarker A, Sharma B, editors. The Lentil: Botany, Production and Uses.

[11] Sarker A, Erskine W. Recent progress in the ancient lentil. The Journal of Agricultural

[12] Kumar S, Kumar J, Singh S, Ahmed S, Chaudhary G, Sarker A. Vascular wilt disease of

[13] Sharpe AG, Ramsay L, Sanderson LA, Fedoruk MJ, Clarke WE, Rong L, Kagale S, Vijayan P, Vandenberg A, Bett KE. Ancient orphan crop joins modern era: Gene-based SNP discov-

[14] Basler F. Weeds and their control. In: Webb C, Hawtin G, editors. Lentils. Farnham, UK:

[15] Riccioni L, Haegi A, Valvassori M. First report of vascular wilt caused by *Fusarium redo-*

[16] Hamdi A, Hassanein AM. Survey of fungal diseases of lentil in North Egypt. LENS

[17] Khare MN. Diseases of lentil. In: Webb C, Hawtin G, editors. Lentils. Farnham Royal,

[18] Stoilova T, Chavdarov P. Evaluation of lentil germplasm for disease resistance to fusarium wilt (*Fusarium oxysporum* f. sp. lentis). Journal of Central European Agriculture.

[19] Bayaa B, Erskine W, Singh M. Screening lentil for resistance to fusarium wilt: methodol-

[20] Vasudeva RS, Srinivasan XV. Studies on the wilt disease of lentil (*Lens esculenta* Moench.).

[21] Khare MN, Agrawal SC, Jain AC. Lentil diseases and their control. Technical Bulletin.

[22] Chaudhary RG, Dhar V, Singh RK. Association of fungi with wilt complex of lentil at different crop stages and moisture regimes. Archives of Phytopathology and Plant

[23] Chaudhary RG, Saxena DR, Dhar V, Singh RK, Namdev JK.Prevalence of wilt-root rot and their associated pathogens at reproductive phase in lentil. Archives of Phytopathology

[24] Agrawal SC, Singh K, Lal SS. Plant protection of lentil in India. In: Erskine W, Saxena MC,

editors. Lentil in South Asia. Aleppo, Syria: ICARDA; 1993. pp. 147-165

Theoretical and Applied Genetics. 2004;**108**:1265-1273

Wallingford: Comm. Agric. Bureau Int.; 2009. pp. 229-247

lentil: a review. Journal of Lentil Research. 2010;**4**:1-14

ery and mapping in lentil. BMC Genomics. 2013;**14**:192

ogy and sources of resistance. Euphytica. 1997;**98**:69-74

*lens* on lentil in Italy. Plant Disease. 2008;**92**:1132

Science. 2006;**100**:19-29

CAB; 1981. pp. 143-154

2006;**7**:121-126

Newsletter. 1996;**23**(1/2):52-56

England, UK: CAB; 1981. pp. 163-172

Indian Phytopathology. 1952;**5**:23-32

Jabalpur, India: JNKVV; 1979. p. 29

and Plant Protection. 2010;**43**(10):996-100

Protection. 2009;**42**:340-343
