Double-Haploid Lentils: High Speed Global Genetic Delivery System

Lentil is an economically important pulse crop for Canada produced mainly for the export market. In conventional breeding programs, several segregating generations must be grown in order to reach a certain level of homozygosity that allows the selection of traits of interest. In contrast, double-haploid (DH) technology produces instant homozygosity and thus can significantly reduce the time required for developing new varieties. The efficiency of the lentil breeding program will also be improved through the reduction in the population size required for screening. DH technology is also required for the development of molecular markers and can provide new selection strategies. These strategies will help in faster development of improved lentil varieties while reducing the costs involved in cultivar development to the breeding program.

DH plants are usually produced through a process called androgenesis in which haploid plants are either directly generated from isolated microspores (immature pollen) or indirectly through the culture of anthers containing microspores. Pulse crops are considered recalcitrant to this technology but pyramiding multiple stresses may be the way to trigger the switch from normal pollen development to the androgenetic pathway. This project aims to elucidate the triggers required for lentil DH and to develop suitable methods via combinations of different stress treatments like temperature, centrifugation, electroporation, sonication, high osmotic liquid media as well as others.

Fig. 1 Flower buds (A) with yellow-greenish anthers (B) which contain uni-nucleated microspores (C) were used for lentil DH induction. (D) shows the symmetrical nuclei division of the microspores after cold treatment. This is the first step for androgenesis induction.