Clonally Propagated and Seed-derived Papaya Orchards: I. Plant Production and Field Growth

Abstract

<jats:p>Papaya seedlings segregate for sex expression as females or hermaphrodites. Typically only hermaphrodite fruit are marketed in Hawaii. The agronomic practice of growing multiple seedlings that are later thinned to a single hermaphrodite tree is wasteful of seed, labor, and resources, especially when seed is costly. We compared growth of plants propagated by the clonal methods of micropropagation or rooting vegetative cuttings versus plants initiated as seedlings and transplanted. The seedlings were either single-planted hermaphrodites as identified by the polymerase chain reaction (PCR) or multiple-planted, thinned seedlings. The experiments were carried out in three different locations on two islands in Hawaii. Clonally propagated plants were significantly shorter than seedlings and bore flowers earlier and lower on the trunk at all locations. Stem diameter differences were not significant even though plant size was different at planting time. Percentage of trees in bud varied significantly in the third month after transplanting when about 90% of the rooted cuttings and large micropropagated plants had formed flower buds while only one multiple-planted seedling developed a bud. Overall, the clonally propagated plants were more vigorous and earlier bearing than were the seedling plants. There is good potential for adoption of clonal propagation when production becomes efficient enough to compete in price with the current practice of over planting and thinning.</jats:p>

Physicochemical and biochemical characterization of transgenic papaya modified for protection against Papaya ringspot virus

“…Generally, female papayas had a smaller shape index and greater mass than the hermaphrodite fruits (P < 0.05; Table 1); wileyonlinelibrary.com/jsfa this is not unexpected since in comparison to hermaphrodite fruits female papayas are typically more compact. 12,13 There were no significant differences in the shape index (Table 1) of the female non-transgenic and transgenic papayas; however, for the hermaphrodite fruits only transgenic line 52.22 was similar to the non-transgenic papaya in shape. Fruit masses were non-uniform (P < 0.05), with the exception of line 52.3 and nontransgenic hermaphrodite papayas.…”

Clonally Propagated and Seed-derived Papaya Orchards: II. Yield Comparison

“…'Rainbow' seeds were gifts of Richard Manshardt, University of Hawaii. Methods involved in the production of in vitro-grown micropropagated plants, cuttings rooted in the greenhouse, PCR-identifi ed hermaphrodite seedlings, and multiple-planted, thinned seedlings used for the experiment were described previously (Fitch et al, 2005).…”

“…Cropping systems using hermaphrodite plants would eliminate multiple-planting and the competition and thinning associated with this practice. Fields can be established with clonally propagated rooted cuttings (Allan, 1964(Allan, , 1993 or micropropagated plants (Chan and Teo, 2002;Drew, 1988;Drew and Vogler, 1993;Fitch et al, 2005). Growth of micropropagated 'Rainbow' papayas (Manshardt, 1998) was compared to rooted cuttings, single hermaphrodite seedlings, and thinned seedlings in three locations in Hawaii (Fitch et al, 2005).…”

“…Fields can be established with clonally propagated rooted cuttings (Allan, 1964(Allan, , 1993 or micropropagated plants (Chan and Teo, 2002;Drew, 1988;Drew and Vogler, 1993;Fitch et al, 2005). Growth of micropropagated 'Rainbow' papayas (Manshardt, 1998) was compared to rooted cuttings, single hermaphrodite seedlings, and thinned seedlings in three locations in Hawaii (Fitch et al, 2005). That study corroborated those of Allan (1964), Chan and Teo (2002), Drew (1988), and Drew and Vogler (1993) by showing that rooted cuttings and micropropagated plants fl owered earlier and lower on the trunk compared to seedlings.…”

Miniestaquia de mamoeiro hermafrodita ‘Golden’ com indutor auxínico, em sistema semi-hidropônico

“…Pelo fato da propagação do mamoeiro ser sexuada e, não se conhecer, visualmente, o tipo floral da planta antes do florescimento, a solução é o preparo e plantio de mais de uma muda por cova (ALLAN 2013, SCHMILDT et al 2015. Para variedades como o 'Golden', tem-se recomendado plantar três mudas por cova, o que proporciona, após a adequada sexagem (desbaste das mudas femininas), cerca de 96% de plantas hermafroditas na lavoura, implicando em aumento dos custos de produção (SCHMILDT et al 2015), além de afetar o desenvolvimento das plantas hermafroditas em razão da competição por água, luz e nutrientes minerais (FITCH et al 2005, FERREIRA et al 2011.…”