A simple and efficient method of in vivo rapid generation technology in pea (Pisum sativum L.)

In the plant breeding cycle, the length of time from seed to seed is often a limiting factor in producing pure lines or recombinant inbred lines (RILs). The objective of this research was to accelerate the production of field pea RILs while maintaining the population size, through application of a technique referred to as 'rapid generation technology' (RGT). The effect of plant hormones and growth conditions were evaluated for two pea cultivars then the optimum combination was applied in the development of RILs from a cross between cultivars CDC Dakota and CDC Amarillo over seven generations. In an average of 33.4 d, 100% of plants flowered when the following conditions were applied in the final in vivo protocol: 0.6 mu M flurprimidol, 266 plants per square meter, 20 h photoperiod, 21A degrees C/16A degrees C light/dark, hydroponic system with vermiculite substrate, scheduled fertilizer application, and 500 mu M m(-2) s(-1) light intensity using T5 fluorescent bulbs. Seed setting occurred in 97.8% of plants per generation within 68.4 d. This approach was 30-45 d per generation faster than conventional single seed descent (SSD) methods. Therefore, RGT could increase plant generations per year using much less growth space compared to SSD, and in this way rapidly address new pulse breeding objectives using a fast (5.3 generations per year), reliable (97.9% survival rate), easy, and inexpensive (in vivo instead of in vitro) protocol.