Diallel analysis of cassava brown streak disease, yield and yield related characteristics in Mozambique

作者：Zacarias A M; Labuschagne M T^*

来源：Euphytica, 2010, 176(3): 309-320.

DOI：10.1007/s10681-010-0203-2

• Cassava brown streak disease
• Combining ability
• Heritability
• Resistance
• Yield

Cassava brown streak disease (CBSD) reported from 1999 in Mozambique, now constitutes the main production constraint in the country. CBSD may be found in all plant parts, affecting food security and availability and quality of planting material. The aim of this study was to evaluate the relative importance of general (GCA) and specific combining ability (SCA), and inheritance of relevant traits and to identify superior parents for use in further improvement of genotypes for yield and CBSD resistance. The parents were selected from a region where CBSD is the main economic constraint. Chigoma mafia was the best general combiner for average root number and CBSD resistance, Mulaleia also combined well for CBSD resistance. Clone IMM 30025 was the best general combiner for root pulp hardness, but combined poorly for CBSD resistance. Chigoma mafia x Mulaleia had the best mean performance for fresh root yield and CBSD resistance. Macia 1 x Chigoma mafia had the best SCA for fresh root yield, CBSD resistance and root pulp hardness. MZ 89186 x IMM 30025 and the reciprocals IMM 30025 x MZ 89186, Chigoma mafia x Macia 1 and MZ 89186 x Mulaleia had the best resistance to CBSD. This indicates that there is good parental material for CBSD resistance breeding. Chigoma x Mulaleia, MZ 89185 x IMM 30025 and MZ 89186 x Macia 1 had good mid-parent heterosis for the most important traits. Broad sense heritability estimates varied from 38.9 for fresh root yield to as high as 95.5 for harvest index, indicating the potential for effective response to selection.

• 出版日期2010-12