TM3x: triploid black sigatoka-resistant Musa hybrid germplasm.

摘要

Tropical Musa secondary hybrids (TM3x) were selected from tetraploid-diploid crosses, and were tested in Onne, Nigeria. The female parents of TM3x were black sigatoka (Mycosphaerella fijiensis)-resistant primary tetraploid hybrids (TMPx) derived from diploid-triploid crosses. The male parents were either diploid hybrids selected in Honduras (SH), or were plantain-derived diploids (TMP2x) from Nigeria and derived from triploid-diploid crosses. The origins of PITA-15 (TM3x 15108-2), PITA-16 (TM3x 15108-6), PITA-19 (TM3x 15108-1) and PITA-20 (TM3x 14604-35) are given, and the hybrids are described. These TM3x hybrids outyielded their polyploid parents and grandparents at Onne, but fruits of PITA-19 were smaller than those from the plantain landracesBobby Tannap and Obino l'Ewai. All TM3x hybrids showed partial resistance to M. fijiensis, and PITA-16 was free from banana streak badnavirus (BSV) and cucumber mosaic cucumovirus (CMV). Of the TM3x cultivars, PITA-15 had the best fruit quality, and itsunripe boiled fruits were often preferred in taste tests to the plantain landrace Agbagba. PITA-20 had a short growth cycle, and so had higher potential annual yields (20 t/ha) than PITA-16 (19 t/ha) or Bobby Tannap (9.9 t/ha). PITA-20 has more plantainalleles than PITA-15 and 16. It is suggested that the development of TM3x implies that heterosis for bunch mass and yield potential can be achieved by maximizing heterozygosity through crossing unrelated parents (e.g., PITA-16 from TMPx 4479-1 X SH-3362), or by proper selection within populations of hybrids derived from full-sib parents (e.g., PITA-20). Using PCR analysis with 33 random primers, 3 primers were selected to analyse the hybrids. A single primer, Ma-3-139, generated unique simple sequence length polymorphisms for each hybrid, although the accumulation of banding patterns generated by Ma-3-139 and Ma-0-48 was necessary to distinguish the hybrids from all of the parent and grandparent genotypes.