Genetically modified sweet pepper (Capsicum annuum) may originally originate from cultivation in Mexico. This original wild pepper may be the ancestor of today's sweet pepper and genetically modified sweet pepper in China with an inserted gene for resistance to Cucumber mosaic virus. Genetically modified GM sweet pepper (PK-SP01) was developed in 1998. Beijing University was granted permission for commercial release in 1999. GM sweet pepper is grown in Fujian and Yunnan provinces. It may be that it is grown mostly in the Fuijan area because high number of outbreaks of CMV on their tomato crops.
Wild pepper (C. annuum var. Glabriusculum), the ancestor of the garden plants C. annuum, is a perennial shrub that produces dozens of erect, spherical, pea-sized fruits. The plants are found widely in northern Mexico. Seeds from these plants, which still grow in the wild, can be transported and spread well by birds that eat the fruit. Cultivated plants of sweet pepper (Capsicum annuum) can originate from both central-eastern and north-eastern Mexico from as far back as 6500 years ago. Spanish pepper garden plants were later introduced to Indonesia in the 16th century, probably by Portuguese and Spanish sailors.
The hot taste of some pepper fruits is mainly controlled by concentrations of capsaicin. Capsaicin is an anti-grazing substance in chili peppers. In mammals, capsaicin in contact with the mucous membranes causes a burning sensation. It also reduces the growth of fungi, and keeps the fruit fresh longer. The mild sweet taste of sweet pepper makes it very popular as a roasted or grilled vegetable in many Asian dishes as well as raw food in salads. More than two-thirds of the world's sweet pepper is produced in Asia. China is the largest producer of sweet pepper.
Sweet pepper PK-SP 01 was first developed by Beijing University in China in 1998. This sweet pepper has inserted the cmv-cp gene (Cucumber mosaic virus coat protein gene) to give the plant resistance to a virus; pickle mosaic virus. This inserted gene codes for ncRNA (non-coding RNA) which replicates itself in the plant cells. The biosecurity certificates for sweet pepper PK-SP 01 have expired. However, marketing of seeds and propagating materials other than seeds is permitted. Sweet pepper incident PK-SP 01 may still be in production, but without a biosecurity certificate this pepper cannot be imported.
There are other viral diseases against pepper. Some of the most common are Tobacco mosaic virus (TMV), and Tomato mosaic virus (ToMV), which can infect over 200 different plant species. In addition, there is the Potyvirus group with Tobacco etch virus (TEV), and Pepper mottle virus (PepMoV). Both of these two types of potyvirus can be very damaging to pepper. These viruses can be transported and transmitted through aphids. Plant viruses can also be transmitted by whiteflies and thrips.
Resistance in sweet pepper to CMV can be better achieved through crosses between different hybrids with CMV resistance and other desired characteristics of sweet pepper. For each generation, it can be selected for CMV resistance. CMV resistant crops can then be crossed with other hybrids with other desired traits such as earliness, yield, shell thickness, and more. Resistance to CMV is composed of several genes, the development of new resistant variants is therefore possible but not easy.
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