Читать книгу Principles of Plant Genetics and Breeding - George Acquaah - Страница 272

In artificial pollination, the breeder should be familiar with the species to know its flowering habits regarding time from planting to flowering, duration of flowering, mechanisms and timing of natural anther dehiscence and fertilization, and time of peak pollen production, in order to take advantage of the window of opportunity of anthesis (pollen shed) for best crossing outcomes. To ensure that parents in a crossing program will have flowers at the same time, the practice of staggered planting is recommended: to plant sets of parents at different times. This way, a late‐planted early flowering genotype may be pollinated by an early‐planted late flowering genotype. When depending on natural pollination, interspersed planting on different dates will favor even pollen distribution.

Photoperiod may be manipulated in photoperiod‐sensitive species to delay or advance flowering as appropriate, in order to synchronize flowering of the parents in a cross. Other techniques that have been used in specific cases include manipulation of temperature and planting density, removal of older flowers to induce new flushes of flowers, and pinching (e.g. removal of plant apex to induce tillering or branching for additional flowers). In corn, the silk of an early flowering inbred parent may be cut back to delay the time to readiness for pollination.