Experiments of Knight and Goss on pea Knight (1799) and Goss (1824) had conducted experiments on edible pea (Pisum sativum), much before Mendel, but failed to formulate the laws of inheritance, only because they could not give a mathematical treatment to their results. Knight was interested in improvement of fruits and vegetables and used to live in England. He crossed two varieties of pea : (i) unpigmented variety with green stem, white flowers and white seed coats and (ii) pigmented variety with purple stejpif purple flowers and grey seed coats. When unpigmented variety was pollinated by pollen from pigmented variety, only pigmented progeny appeared, which on selfing or on pollination by unpigmented variety produced both kinds of progeny in the next generation. Since he did not keep any record of number of two different kinds, he could not discover the mechanism of inheritance, and only concluded that there was a 'stronger tendency' to produce pigmented plants than unpigmented ones. Knight also noticed that the reciprocal crosses gave similar results.
Goss (1824) made similar crosses and used green seeded and yellow seeded varieties. In first generation, he got all yellow seeds and in succeeding generation derived due to selfing, he got (i) few pods with green seeds, (ii) fev pods with yellow seeds and (iii) many pods with green and yellow seeds. In the third generation he noticed that green seeds gave only green seeds, but yellow seeds gave either only yellow or yellow and green both. These results are similar to those obtained by Mendel, forty two years later (Mendel, 1866). The main reason for the failure of Knight and Goss in understanding the mechanism of inheritance, was firstly due to lack of numerical treatment of data and secondly due to their main concern for improvement of peas rather than their concern for understanding the mechanism.
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