Molecular breeding by genetic transformation

Fig. 22.1. Schematic presentation of transfer of Xa-21 from original source to cultivated rice by conventional and molecular breeding. From Datta, 1998.5

PR genes in intra- and extracellular tissue provides enhanced fungal resistance, which allows a reduced application of fungicides. We have introduced a PR-5 gene, D34 (thaumatin-like protein gene), in rice, which showed enhanced resistance to sheath blight (Fig. 22.2b).11 We are now aiming to develop transgenic rice with multiple genes, and assume that this is a better strategy for durable resistance because of gene pyramiding (Table 22.5).

Transgenic Rice With Xa-21 Conferring Resistance To Bacterial Blight

Bacterial blight (BB) caused by Xantho-monas oryzae pv. oryzae (Xoo) is one of the most destructive diseases of rice throughout the world. A schematic presentation compares conventional breeding and the relative advantage of molecular breeding with Xa-21 (Figs. 22.1 and 22.2c). However, durable resistance can be achieved only with gene pyramiding, as was done in transgenic IR72. This is a very efficient way to improve BB resistance in a desirable cultivar without the negative impact of genetic linkage dragging.

Organic Gardeners Composting

Organic Gardeners Composting

Have you always wanted to grow your own vegetables but didn't know what to do? Here are the best tips on how to become a true and envied organic gardner.

Get My Free Ebook


Post a comment