Spike proliferation in black pepper (Piper nigrum L.)

Abstract

Introduction. Black pepper (P. nigrum L.), the major world spice, is a climbing vine of historical, religious and economic importance. Landraces or farmer’s cultivars constitute the major component of this tropical vine's diversity. Normal spike formation. Berries of P. nigrum are produced in solitary, unbranched, axillary spikes. The apical bud of the plagiotropic branches transforms into an inflorescence (spike). Spike variant. Mutation in the floral meristem of black pepper could result in inflorescence proliferation. A variant with 100% of proliferating spikes was collected from a farmer’s plot, and then propagated by cuttings. The proliferating spikes are of indeterminate growth habit. Benefits. This natural mutant of Piper nigrum resulted in improved socioeconomic status of the farmer through sale of the rooted cuttings at a premium price. The variant can also be used as a donor for improvement of black pepper, besides as a novelty in potted pepper culture. Since berries of varying maturity are produced due to indeterminate growth, and since immature berries are rich in oleoresin, a single harvest will be yielding matured berries, which can be traded as black pepper of commerce, and half-matured berries suited to the value-added industry. Discussion. Mutations in the floral organ identity genes and their effect on altered flower/inflorescence development have been reported in the literature. In the case of spike proliferation, the transformation of the floral primordia in the mutant spike into inflorescence primordia has resulted in the modified spike architecture.