BANANA IN VITRO MUTATION BREEDING

BANANA IN VITRO MUTATION BREEDING is a new technology in planting material mass production for banana. Edible bananas are mostly sterile polyploids and must be propagated vegetatively, hence genetic improvement through cross-breeding is not possible. Mutation breeding has been suggested as an excellent alternative approach for banana improvement. In addition, the heterozygosity of asexual banana clones makes them suitable for mutation induction. The heterozygotic status is expected to be Aa in loci of diploid cultivars while the triploids of A genomic types can exist in either Aaa or Aaa forms. For interspecific hybrids, the heterozygotic constitution could be AaB, Aab, AAb, ABb, aBb or aBB. Mutation induction may uncover a recessive phenotype by mutating, inhibiting or deleting the corresponding dominant allele.

The use of cultured shoot tips for mutagenesis has facilitated mutation induction and the regeneration of potential mutants. An early flowering mutant of Grand Naine, GN-60Gy A, which also showed differences in the zymograms of soluble proteins and esterase isozymes, was induced by Novak after exposing shoot tips to gamma radiation. Further selection of GN-60Gy A in Malaysia has resulted in the release of an early fruiting Cavendish banana called Novaria. Matsumoto and Yamaguchi selected an aluminium-tolerant mutant from irradiated protocorm of a Cavendish banana.

Pisang Berangan (AAA) is a popular dessert banana, having good fruit quality, flavour, colour, pulp texture, size and shelf life. However, it is relatively tall and very susceptible to Fusarium wilt (Fusarium oxysporium f.sp cubense) and freckle disease caused by Cladosporium musae. Consequently, a mutation breeding program was initiated using gamma irradiation to induce genetic variation so that plants could be selected with one or more of the following characteristics: (a) tolerance to Panama disease; (b) short plant stature; and (c) early fruiting and high bunch weight. The present review aims to present the current status of the research, problems encountered, and research strategies. This short report adapted from a study by FAO. Further information linked to :http://www.fao.org/docrep/007/ae216e/ae216e08.htm

By
M Anem,
Senior Agronomist
Dole Cavendisf Commercial Farm
Hulu Bernam
Selangor,
Malaysia.