Frequently Asked Questions
- The Vitaceae (grape family) consists of many diverse species which grow in a range of climates. The species Vitis vinifera from the Vitis genus is the major cultivated grape crop.
- The 1C genome size of Vitis vinifera is relatively small, approximately 480 Mbp.
- The genome is diploid, though tetraploid and triploid plants have been produced.
- Chromosome number is 2n = 38 for species in the Vitis genus.
- Chromosome number is 2n = 40 for species like Muscadinia rotundifolia which is also known as Vitis rotundifolia.
- BAC libraries, cDNA libraries, microsatellite markers, EST sequences and drafts of the genome sequence are available.
- Vitaceae DNA and protein sequences held in GenBank public databases.
- The main cultivated species Vitis vinifera is of euroasian origin. It is known for the quality of its grape berries but it is susceptible to many pests and diseases.
- Non-vinifera species in North America have many desirable traits including resistance to pests and diseases.
- The genetics of many traits are unknown.
- Populations for genetic mapping and germplasm collections holding unique genotypes are available.
Breeding and Reproductive Biology
- Grapevine cultivars are highly heterozygous and inbreeding depression has been reported to be common.
- Seedlings can take three years or longer to produce fruit under normal vineyard management conditions.
- Flowering and fruit ripening in the vineyard is a long process. For example, in the Southern Hemisphere the inflorescences initiated in latent buds during October-December 2000 will flower and set fruit in September-October 2001 with fruit ready for harvest in March-May 2002.
- Cultivated Vitis vinifera varieties produce hermaphroditic flowers. Wild-type vines are dioecious and have either male or female flowers.
- The release of a new wine grape variety can take 20 years or longer from seed to commercialisation due to the need for extensive field trials and wine evaluation.
- Biolistic and Agrobacterium transformation systems exist for a number species including V. vinifera. Wine and table grape cultivars have been transformed including; Sultana, Chardonnay, Cabernet Sauvignon, Shiraz, Reisling and others.
- Field trials of transgenic vines are in progress in Europe and non-European countries.
- The plant is a perennial deciduous woody vine with a unique shoot architecture.
- The non-climacteric, fleshy fruit has novel secondary metabolism producing colour pigments, tannins, flavour and aroma compounds.
- Grapevine cultivars are clonally propagated by vegetative cuttings.
- Cuttings planted under normal vineyard management conditions usually produce fruit suitable for harvest in the third year with full production in six years.
- Grapevines grow well under glasshouse conditons but floral induction and fruit production is often poor.
- Considered to be the world's major horticultural crop. Wine, fruit juice, fresh fruit and dried fruit are the main products.
- Hectares in the world under grapevine cultivation in 2000 was 7.7 million hectares.
- World grape production in 2000 was 64,029,460 Mt.
- World wine production in 1999 was 28118 million litres.
- A useful source of agriculture statistics are the FAOSTAT databases. For wine statistics go to the Australian Wine and Brandy Corporation site or the International Organisation of Vine and Wine.