The value of Hybrids “No product of the plant breeder’s art or science has had greater impact on increasing the world’s feed or food resources than hybrids”. 1 16 COURIER 2/06
Hugely successful in corn, the use of hybridization by plant breeders to improve crop productivity is now prevalent in a vast array of cereal, horticultural and vegetable crops. <strong>Bayer</strong> <strong>CropScience</strong> has developed an expertise in the production of quality hybrid seed in canola and, to a smaller extent, cotton and in the most recent crop embracing hybrid vigor, rice. Breeding and plant pollination A hybrid is the result of a cross between two genetically distinct parent lines. When the right parents are selected, a hybrid will have both greater vigor and yield than either of the parents. Hybrids also tend to have increased resistance to diseases and insects. The process of breeding hybrids, “hybridization”, is achieved through the use of what is called a pollination control system that renders the pollen of one parent line non-viable (male sterile or female line) to ensure pollination by the chosen parent line. One of the most common methods to eliminate self-pollination is emasculation through the mechanical removal of the anthers. In corn, where the male flowers are separated from the female flowers, the process is called “detasseling” and involves the removal of the male flowers from the plant. Genetic methods can also be used to generate the desired male sterility in hybrid seed production, particularly in crops that possess full or “perfect” flowers (male and female) and that “have a moderate degree of out-crossing, produce few seeds per flower, and for which the costs of manual castration techniques cannot be recovered by the price of the seed.” 2 Why Farmers use F1 Hybrids There are three very good reasons why farmers are interested in first generation filial (F1) hybrids. The first is to obtain higher yields through a phenomenon known as hybrid vigor (heterosis) or heterozygote advantage. The second is uniformity. Every plant in an F1 is identical (with some genetic variation in the inbreds that gets multiplied when the inbreds are crossed) and this uniformity can be advantageous when you are trying to harvest a field at one time, by a machine. The third is the availability of certain hybrid gene combinations that are only present in a commercial F1 and that are technically impossible in an inbred line. If farmers plant the seeds of a hybrid crop (F2, F3…), then the resulting crop will deliver disappointing results. The growth will not be uniform, harvests will show mixed grain types and will have lost its yield advantage. <strong>For</strong> this reason, a fresh batch of F1 hybrid seed should be planted for every crop. Indeed, from a farmer’s perspective, hybrids are best used when the increased yields from hybrid vigor will more than pay for the extra cost of planting seed; the added premium being uniformity. 3 Producing Commercial F1 Seed The production of commercial hybrid seed for sale to farmers is an expertise intensive – as opposed to capital intensive – exercise. It requires considerable agronomic and genetic expertise to produce quality seed in general and hybrid seed in particular. Within <strong>Bayer</strong> <strong>CropScience</strong>, the process begins with our expert breeders developing and then selecting the most desirable parent lines to form a high quality male and female gene pool. Once selected, these lines are handed over to our expert ‘Parent Seed Team’ to be grown and multiplied. The parent lines are then coded and dispatched to contracted farmers who will grow the seed under the supervision of our Certified F1 Seed Production Team. The team is comprised of expert breeding and production agronomists who ensure the quality and grade of the seed throughout the product cycle. The parent lines are kept separate in the field and are often sown at different times to ensure the synchronized development (flowering) of the male and female lines and to maximize cross-pollination. The team works with the contracted farmers who are paid a premium for growing the coded parent lines in accordance with the specified protocol. The harvested seed is then sent back from the farms to <strong>Bayer</strong> <strong>CropScience</strong> for quality evaluation and grading and is cleaned, treated, coated, bagged and distributed. 1+2) Introduction to Plant Breeding – Briggs & Knowles 1967 3) Ibid 2/06 COURIER 17
Change language