Look at this list of characteristics of strawberry plants. Plants will not die in temperatures below 4ºC Big strawberries Plants produce lots of strawberries strawberries are bright red strawberries stay fresh for a week after picking Plants are resistant to disease strawberries are juicy strawberries are very tasty Small strawberries Plants have small leaves Strawberries rot quickly Which characteristics are important to: a) A farmer, b) A shopper? If you were a plant breeder, which 5 characteristics would you like your new variety of strawberries to have? Explain your choices. Plants can survive with little water.

A farmer grows two different varieties of strawberry plant. Variety A grows small but very tasty strawberries. Variety B grows large but tasteless strawberries. Suggest to the farmer what he could do to improve the quality of his strawberries.

If he breeds the two plants together then the offspring will have a variety of their parent’s characteristics. To get the best strawberries (large and tasty) the farmer must breed together the best two offspring, and keep repeating this over and over until he gets the perfect strawberry.

Farmers can breed two different plants together by using cross-pollination. First the farmer must decide which plant is to produce the pollen (flower A) and which will receive the pollen in its stigma (flower B). These must be clearly marked, perhaps with different coloured thread or a tag. The next step is to ensure that flower B is not fertilised by its own pollen (self- pollination). Some farmers remove the anthers (the male parts, which produce pollen) with tweezers. They may need a magnifying glass to do this. To prevent fertilisation from another flower farmers tie up the petals of the flower with a piece of string or put a polythene bag over the flower to protect the stigma. To cross pollinate the farmer rubs a paint brush over the anthers of flower A. They then remove the protector from flower B and rub the pollen over its stigma. Hopefully fertilisation will happen and a new plant is made (a mixture of the characteristics from both plants).

Your task is to write an article for Plant Growers Weekly about using selective breeding to grow better plants. You need to explain: Why a plant grower should use selective breeding and How they can carry it out Your article must be aimed towards: A farmer who grows tomatoes to sell to supermarkets or A person who grows prize-winning tulips to enter shows (prize winning tulips have long stems and large brightly coloured flowers)