In recent years the potential of genetic manipulation of Coffea using recombinant DNA technology and tissue culture techniques has been heavily explored by introducing new genes for characteristics such as resistance to pests or to herbicides, or genes coding for desirable cup quality attributes, it may be possible to produce plants with any combination of features required.

Below are core techniques used in coffee breeding today:

1. Controlled pollination and multiplication by seed
2. Vegetative propagation

• Traditional methods: grafting, taking cuttings
• New tissue culture methods: micro propagation, somatic embryogenesis

Robusta
Robusta is diploid and self-sterile, producing many different forms and varieties in the wild. The identification of cultivars is confused, but two main forms are recognized:

• Robusta — upright forms
• Nganda — spreading forms

Arabica
Arabica is a tetraploid (44 chromosomes) and is self-pollinating. There are two distinct botanical varieties: Arabica (typica) and bourbon. Historically, typica was cultivated in Latin America and Asia, whereas bourbon arrived in South America and later, East Africa via the French Colony of Bourbon. Because Arabica is self-pollinating, these varieties tended to remain genetically stable. However, spontaneous mutations with desirable characteristics have been cultivated in their own right, as well as exploited for cross-breeding. Some of these mutants and cultivars are described below.

Mutants:

• Caturra–a compact form of bourbon
• Maragogipe–a mutant typica with large beans
• San Ramon–a dwarf typica
• Purpurascens–purple leaved forms

Cultivars have been developed to give the maximum economic return under specific regional conditions such as climate, soil, methods of cultivation and the prevalence of pests and diseases. Some of the better known cultivars are:

• Blue Mountain–grown in Jamaica and Kenya
• Mundo Novo–a cross between typica and bourbon, originally grown in Brazil
• Kent–originally developed in India, showing some disease resistance
• Catuai–developed as a hybrid of Mundo Novo and Caturra, characterized by either yellow or red cherries: Catuai-amarelo and Catuai-vermelho respectively.

Arabica / Robusta hybrids
Coffee has been selectively bred to improve characteristics of: growth and flowering, yield, bean size and shape, cup quality, caffeine content, disease resistance and drought resistance.

Crosses between Arabica and Robusta aim to improve Arabica by conferring disease resistance and vigor, or to improve the cup quality of Robusta. Below are some of the better known hybrids:

• Hibrido de Timor is a natural hybrid of Arabica x Robusta which resembles Arabica coffee and has 44 chromosomes.
• Catimor is a cross between Caturra and Hibrido de Timor and is resistant to coffee leaf rust disease.
• Ruiru Eleven is a dwarf hybrid which is resistant to coffee berry disease and to coffee leaf rust. It is also high yielding and suitable for planting at twice the normal density.
• Icatu hybrids are the result of repeated backcrossing of interspecific Arabica to Robusta hybrids to Arabica cultivars Mundo Novo and Caturra.
• Arabusta hybrids are fertile interspecific, hybrids from crosses between Arabica and induced auto-tetraploid Robusta coffee.