b'EDITORS MESSAGEWHATS SO SPECIAL ABOUT HYBRIDS ANYWAY?high-quality vegetables on the groceryright parent lines and finding the right shelves. But perhaps its good we brieflyparent line combination that leads to the take a few steps back and see where itbest performing hybrid in a certain envi-all began. The realization that the cross- ronment. This leads to a slightly higher ing of carefully selected parent linesseed price, which in basically all cases can create a hybrid plant variety thatis earned back by the higher yield and (well) outperforms the best parent linebetter performance of the hybrid. Self-was done by several people, more or lesspollinating the F1 hybrid plants leads to simultaneously.a heterogeneous and segregating popula-It was Charles Darwin himself who,tion, which is not expressing the hybrid in 1876, wrote down his theory of hybridvigour. This makes it less attractive for vigour. A year later, William James Beal,a farmer to save seeds. Another draw-became the first to cross-fertilize corn forback could be that all plants mature at the purpose of increasing yields throughthe same time, which leads to a peak in hybrid vigour. In 1881, Eugene Davenportharvest labour and produce. For some a and Perry Holden published an account ofbenefit, for others a drawback.a field experiment demonstrating hybridThere are many examples of the ben-Marcel Bruins vigour in corn.efits: nearly all field corn exhibits hetero-In1906,HermanNilsson-Ehlesis and corn yields in the U.S. increased pointed out that part of the offspring ofsixfold. Hybrid rye varieties give 10-20 T his year marks 145 years sinceexperimentally produced hybrids com- per cent higher yields, improved lodging mankind discovered the benefitsbined the valuable properties of the par- resistance and improved sprouting resist-of hybrid plant varieties. In manyents. Standing on the shoulders of giants,ance compared to open-pollinated varie-crop species, hybrid varieties haveGeorge H. Shull, developed his first maizeties. In Mali, hybrid sorghum varieties can become commonplace, but why is it thathybrids around 1910, but commercial pro- produce a yield of three to four tonnes per we strive for hybrid varieties? And whyduction of them did not begin until 1922.hectare, compared to non-hybrid varieties are certain fringe groups in society stillHe also described heterosis in maize inthat manage two to three tonnes even in questioning their usefulness? 1908 but didnt coin the term heterosisa good season. Hybrid rice varieties have The major reason why hybrids plantuntil 1914. And finally, Edward East,showed a convincing yield superiority varieties are so popular is because of aaround the same time as Shull, observedover previous high-yielding non-hybrid phenomenon called heterosis. Plantthat when the self-pollinated plants werevarieties. Finger millet is one of Kenyas breeders and scientists noticed, thatcross-pollinated to produce hybrid prog- most important drought-tolerant cere-when they began crossing different lineseny, these plants sometimes were evenals, but farmers have not expanded pro-that were homozygous, non-segregatingmore vigorous than the plants from whichduction much because of low yield. The (so called pure) lines, that the result- the inbreds had been developed.recent release of a new hybrid variety ing hybrid plants (so called F1 hybrids)As described above, for farmers(yielding 18 and 2490 kg bags per were usually more vigourous than theirand growers, the higher performancehectare, compared to the maximum 12 parents. They had discovered hybridof hybrids is one of the benefits. Yieldbags per hectare from existing varieties) vigour, also called heterosis. increases of 20 to 50 per cent have beenprovided a welcome boost for the farmers. Over the years, hybrids varietiesrecorded. Another clear advantage is thatIn short, over the past century, have become more and more common- the plants are fully homogeneous and pre- hybrid plant varieties have provided mas-place in a wide variety of crops, and wedictable. The plants mature at the samesive benefits, and helped stave off hunger, have all grown up with plant hybridstime, making harvest and post-harvestever since they were introduced. being all around us. processes easier. We are enjoying the products ofOne of the few drawbacks to hybridMarcel Bruinshybrid varieties on a daily basis, withvarieties is that a large amount of timeeditorial director, European Seedbigger harvests from the fields, andand money goes into the creation of thembruins@seedworldgroup.com4IEUROPEAN SEEDIEUROPEAN-SEED.COM'