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Description
Two practical aspects of biometrical genetics are examined - breeding suitable grasses for lawns, football pitches, etc. and breeding ducks suitable for the English market.
Two practical aspects of biometrical genetics are examined - breeding suitable grasses for lawns, football pitches, etc. and breeding ducks suitable for the English market.
| Module code and title: | S299, Genetics |
|---|---|
| Item code: | S299; 13 |
| First transmission date: | 09-08-1976 |
| Published: | 1976 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:24:09 |
| + Show more... | |
| Producer: | Jean Nunn |
| Contributors: | Denis Gartside; Mervyn O. Humphreys; John Powell |
| Publisher: | BBC Open University |
| Keyword(s): | Biometrical genetics; Duck breeding; Grass breeding; Heritability; Poly-crossing |
| Footage description: | Denis Gartside introduces the programme. He briefly sums up the two basic concepts essential for plant and animal breeding - variation and heritabilty. Mervyn Humphreys, at the University of Liverpool Botanic Gardens, points out some of the grasses which he is evaluating for their potential as future lawn grasses. He lists the features of a good lawn grass and also some characteristics which would be undesirable. Humphreys briefly does the same for grasses bred for sports fields. Humphreys explains poly-crossing, a technique which allows the researcher to examine the heritability of a factor such as height. Humphreys, in a field, looks at the parent grasses and progeny of a poly crossing. He points out that there is a high heritablity in the population for differences such as height and flowering time. Humphreys looks at the next generation of poly crossed grasses. There is very little variation left in their height. Humphreys explains why this uniformity was achieved in such few generations. Denis Gartside with a graph showing height of the populations of grasses above. Gartside explains and discusses the mean and variance of the height character distribution. He points out that the additive genetic variance determines the similarities between parental and offspring generations. John Powell on a farm in Lincolnshire, one of the world's largest duck-breeding organisations. Over film shots of ducks, Powell discusses the need to breed ducks of suitable weight and early killing age to meet the requirements of the British market. Powell explains in detail how, using the three way cross method, the marketable duck was developed on this farm. Film shots of ducks as he talks. Powell explains how the selection process to segregate breeding ducks works. Film shots of ducks being weighed and segregated. Denis Gartside sums up. |
| Master spool number: | 6HT/71836 |
| Production number: | 00525_1181 |
| Videofinder number: | 1002 |
| Available to public: | no |
