**2.8 Virus diseases**

Chemical treatments against cucumber mosaic virus (CMV) are not effective; therefore genetic resistance is considered the primary line of defense. Genetic analysis revealed that CMV resistance in cucumber is quantitatively inherited [77] where as in *Cucumis sativus* var. *hardwickii* (wild relative) is controlled by single recessive gene [78]. The inheritance of resistance to zucchini yellow mosaic virus in cucumber is controlled by single recessive gene (). The genes resistant to viruses has been mapped on chromosome 6 including *psrv* for PSRV, *wmv* for WMV and *cmv6.1* for CMV [77, 79, 80]. Recently, cucurbit aphid-borne yellows virus (CABYV) has been reported in cucumber from India [81].
