In addition, some of the high yielding, disease resistance varieties released were mostly upland varieties.
Among the many varieties released, a few have much greater success, and the area of their cultivation increases.
This study determined wheat genetic gains by evaluating 22 winter/facultative varieties released for rainfed conditions between 1931 and 2006.
Rapid expansion of the planting area of hybrid rice is probably one of the main causes of the BPH crisis because most of the hybrid rice varieties released in China are susceptible to BPH (Hu et al. 2012).
Systematic breeding efforts at ICAR-IARI, New Delhi has helped in improving the grain and cooking quality in PB 1121 as compared to other Basmati rice varieties released earlier (Table 1, Fig. 5).
Nerica: improved varieties released by the African Rice Center (formerly WARDA) that result from artificial hybridization between O. sativa and O. glaberrima followed by two backcrosses to the O. sativa parent.
Three NLL varieties were used in this study; P27255 is a wild variety available prior to domestication of NLL within Australia; Unicrop was one of the first domesticated Australian NLL varieties (released in 1973) as a sweet, non-shattering pod variety, and Tanjil is a more recent variety (released in 1998).
Major modern U.S. soybean varieties released between 1947 and 1988 can be traced back to only 80 accessions from a small area in northeastern China.
In the Drought Tolerant Maize for Africa (DTMA) project managed by CIMMYT and IITA, 57 of the 105 varieties released in 13 countries since 2007 are OPVs [ 13].
Classical breeding has been the only responsible for sugarcane varieties released in the last decades [ 1], although some efforts exploiting genetic modification have been carried out [ 9– 13].
Most of the varieties released in China were clustered in the same subgroup in the dendrogram, suggesting the limited genetic diversity and narrow basis of Chinese sesame cultivars.
