Search For New Sweet Lunin

Press, Volume XCIX, Issue 29330, 8 October 1960, Page 9

Search For New Sweet Lunin

ONE of the greatest disadvantages of the blue lupin is the difficult harvesting of the seed before the explosive twisting of the pod scatters its contents on. the ground. With this in mind, Mr M. J. Brusse, a technician of the Cj-op Research Division at Lincoln, is trying to develop a fodder lupin with a pod that is slow to shed its seed. Normally, the best a. farmer can hope to harvest ,is about 80 per cent, of the lupin seed, with most crops yielding well below this figure. A non-scattering lupin would be of great value, and the easier harvesting would mean cheaper seed and the more widespread growing of the plant for feed, Mr Brusse says. Because the blue lupin species, Lupinus angustifolius, which includes the bitter blue, sweet and Borre varieties, has no strain with slow shedding pods and the non-bursting yellow lupins will not cross with it, other avenues must be investigated. . Samples of lupin seed pave been subjected to gamma radiation at the Wakari Public Hospital in Dunedin from Cobalt 60 sources to induce mutations in the developing embryo of the seed. For this work it has been found that

- the moisture content of the seed a has a bearing on the radiation i damage to the rest of the seed, f To date one mutant of the bitter 1 blue variety has shown increased I, vigour of growth and slower f shedding of seed but it has slow t first growth and the number of a seeds in the pods is fewer. Some s of its descendants have odd vagaries of growth—three seed j leaves or cotyledons, instead of r the normal two; one first leaf t with varying segments instead of s two; and a tendency to bush out a instead of developing an erect e single main stem—which while n only occurring in a few specimens are difficult to explain. r If the bitter blue mutant is capable of transferring its worthwhile characteristics to the sweet _ variety by crossing there may be j a new variety of sweet blue lupin “ one day, but if the result is nega- “ tive it .will mean that Mr Brusse . will have to retrace his steps and * examine other irradiated seed foi 5 promising mutants. The odds against achieving success are in a the order of one chance in a milt lion and the plant which is being n studied at present is only one s which appeared of interest out of - more than a pound of one of the r lines of seed subjected to the it gamma rays.