This article presents the attributes of the first East African highland banana hybrid,‘Kiwangaazi’ (Fig. 1), which was recently selected, released, and added to the national cultivar list in Uganda. The ‘matooke’ hybrid ‘Kiwangaazi’ was conventionally bred at Kawanda by crossing the tetraploid hybrid. ‘1201k-1’ (‘Nakawere’ AAA • ‘Calcutta4’ AA) with the improved diploid ‘SH3217’ AA. The main target was black Sigatoka resis- tance, a disease caused by the fungal patho- gen Mycosphaerella fijiensis, ranked as the most important constraint to the production of the East African highland bananas, espe- cially in the low lands (covering most of central and eastern Uganda). ‘Kiwangaazi’, together with other hybrids was evaluated for black Sigatoka response, nematode and weevil damage, yield, and consumer acceptability. The cultivar was evaluated under the code ‘M9’, and released by the national variety release committee as ‘KABANA 6H’. The name ‘Kiwangaazi’ was coined by farmers who participated in the on-farm evaluation
studies. In the local language (Luganda),‘Kiwangaazi’ means ‘‘long lasting.’’ Due to high pest and disease pressure, banana plan-
tations can only last for 3–5 years, especially
in central and eastern Uganda. However, due to its pests and disease tolerance, farmers observed that ‘M9’ plants remain vigorous after 5 years, hence the name ‘Kiwangaazi’.
Like the East African highland cooking bananas, ‘Kiwangaazi’ is a triploid AAA, but clearly distinct from any other existing ge- notypes. Traits that distinguish ‘Kiwangaazi’ from the parents and other closely related cultivars are presented in Tables 1 and 2. Whereas most of the East African cooking bananas have deep green leaves, pseudos- tems, and fruits, ‘Kiwangaazi’ has pale, shiny color on the leaves, pseudostem, and fruits (Tables 1 and 2).
The cultivar ‘Kiwangaazi’ is maintained by the National Banana Research Program of NARO in Uganda. Farmers can access tissue culture plant from private tissue culture laboratories in Uganda and thousands of farmers have participated in the evaluation and promotion of ‘Kiwangaazi’.
Performance in the field. The response of four promising banana hybrids to black Sigatoka, the primary target constraint, is presented in Table 3. Tissue culture plants were established in randomized complete block design at a spacing of 3 m • 3 m, manure was applied at planting, and regular banana man- agement was followed (Tushemereirwe et al.,) two other banana cultivars, a known resistant variety ‘Yangambi KM5’ and the highly
susceptible East African highland banana ‘Atwarira’, the plants were spaced at 3 m • 3 m, manure was applied at planting, and regular banana management was followed (Tushemereirwe et al., 2003). The plants were infested with 10 weevils (female: male ratio of 1:1) at 9 months after planting and corm damage assessment done at harvest (Kiggundu et al., 2003). Total number of mats per genotype in the trial was counted at a 6-month interval. Our results show that ‘Kiwangaazi’ had considerable tolerance to the banana weevils (Table 4). This banana weevil tolerance of ‘Kiwangaazi’ is further highlighted by a significantly low mat disappearance rate of 8.5% at Kawanda (central Uganda) over a period of 5 years in compar- ison with the highly susceptible local variety ‘Atwalira’ (70.6%; Table 4). Previous re- search has attributed banana weevil resistance to biophysical factors like corm diameter, resin/sap production, corm dry matter content, corm hardness, and suckering ability (number of suckers) (Kiggundu 2000). Gen- erally antibiosis (factors affecting larval performance) rather than antixenosis (attraction) appear to be the most important
resistance mechanism in banana (Gold et al.,2001).
The banana weevils have been contraindi- cated in the short plantation life of banana, especially in central Uganda (Tushemereirwe et al., 2001). Therefore, the results imply that ‘Kiwangaazi’ could be handy in addressing the banana production constraints, espe- cially in central Uganda where the growing traditional cultivars have become difficult due to these pests. This implies that hybrid
The vast majority of the bananas currently grown and consumed were not conventionally bred but are selections made over probably thousands of years from naturally occurring hybrids. Cultivated bananas are very nearly sterile and as a consequence are not propagated from seed but rather through vegetative propagation, primarily suckers as well as more recently micropropagated or tissue cultured bananas. These factors, very old selections, near sterility and vegetative propagation, mean that these bananas have not been genetically improved either for resistance or improved quality and are becoming increasing in affected by serious pests and diseases.
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