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.

Gynodioecious papaya (Carica papaya L.) seedlings in commercial cropping systems in Hawaii are typically multiple-planted and thinned upon fl owering to a single hermaphrodite because seedlings segregate for sex expression. Use of clonally propagated hermaphrodites would eliminate the over-planting practice and may provide other advantages. Yields of clonally propagated hermaphrodites were compared with single-and multiple-planted seedlings in three fi elds on two islands in Hawaii. Cloned hermaphrodites were either rooted cuttings or in vitro micropropagated plants. Clonally propagated plants bore ripe fruit 1 to 3 months earlier than thinned seedlings and had signifi cantly higher early and cumulative yields. At each site, cumulative yields of thinned seedlings never reached the same level as those of clonally propagated plants. The yield benefi t from clonally propagated plants was greatest at Keaau, the lowest sunlight and least productive test site.

FRANK, HILMER A. (University of Hawaii, Honolulu), NORMA A. LUM, AND AMY S. DELA CRUZ. Bacteria responsible for mucilage-layer decomposition of Kona coffee cherries. Appl. Microbiol. 13:201-207. 1965.-The predominant microbial flora present during decomposition of the mucilage layer of Kona coffee cherries were gram-negative bacteria which fermented lactose rapidly. Cultures isolated from coffee cherries undergoing fermentation included species of Erwinia, Paracolobactrum, and Escherichia. Unblemished cherry surfaces and coffee plantation soil also had a microflora containing a high proportion of bacteria belonging to these three genera. Of 168 isolates tested, the 44 strains capable of demucilaging depulped coffee cherries were all members of Erwinia dissolvens. Supernatant growth medium liquids, after removal of E. dissolvens cells, actively decomposed the mucilage layer of depulped cherries.

SUMMARY The mucilage layer of ripe Kona coffee cherries decomposes naturally during processing. Mucilage breakdown does not occur if the cherry surface is disinfected chemically or if the outer skin remains unbroken. Decomposition depends upon the presence of pectinolytic bacteria, not, as sometimes reported, upon enzymatic activity of the coffee cherry.

In this work it was developed marker-free transgenic indica rice plants (cv J-104) by biolistic co-transformation and segregation approach. We attempted to express the NmDef02 antifungal defensin. Primary transformants were regenerated from embryogenic callus on culture medium with 50 mg/L hygromycin. Screening of hpt-marker-free transgenic lines was made by PCR in T 1 progeny lines, germinated on semisolid medium without hygromycin. Relative expression of NmDef02 mRNA was examined by quantitative RT-PCR in marker-free T 1 plants. In vitro antifungal test was performed by disk diffusion assay against Sarocladium oryzae. PCR assay verified that 15.12% of T 1 plants were marker-free (NmDef02+/hpt−). RT-PCR analysis indicated that NmDef02 gene was successfully transcribed and the transgenic lines displayed different expression levels of the NmDef02 cDNA. Protein extracts of marker-free lines with high relative expression of NmDef02 inhibited fungus mycelial growth around disks. In contrast, it was confirmed fungus proliferation on disks impregnated with protein extracts of non-transgenic plants. The results of the present work demonstrated that the expression of the NmDef02 defensin in transgenic rice plants is effective against the phytopathogenic fungus Sarocladium oryzae under in vitro conditions. Thus, NmDef02 defensin could be a useful tool for J-104 rice improvement.