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Beyl, C.A. 1990. Fire blight susceptibility in a young
Asian pear planting. p. 376. In: J. Janick and J.E. Simon (eds.), Advances in
new crops. Timber Press, Portland, OR.
Fire Blight Susceptibility in a Young Asian Pear Planting
Caula A. Beyl
Fire blight (Erwinia amylovora), a bacterial disease native to
North America, is one of the limiting factors for successful commercial
production of pears in the eastern U.S. Increased interest in Asian Pear has
generated questions of its fire blight susceptibility. To evaluate this, a
trial of 18 cultivars on 4 different rootstock including Pyrus communes
'Winter Nelis', P. ussuriensis, P. calleryana, and P.
betulaefolia was established in 1984 on the campus at Alabama A&M
University, Normal, AL. Scion cultivars included 'Chojuro', 'Doitsu',
'Erishinge', 'Hosui', 'Ishiwase', 'Kikusui', 'Kumoi', 'Megeitsu', 'Niitaka',
'Okusankichi', 'Seigyoku', 'Seuri', 'Shinko', 'Shinseiki', '20th Century',
'Ya Li', 'Shin Li', and 'Daisu Li'. In 1986, the best ten cultivars with least
susceptibility to fire blight were 'Doitsu', 'Seuri', 'Hosui', 'Shin Li',
'Megeitsu', 'Ya Li', 'Shinko', 'Erishinge', 'Kikusui', and 'Daisu Li'. In
1988, with the majority of trees bearing and no longer juvenile, the three best
cultivars were Shinko', 'Ya Li', and 'Shin Li' closely followed by 'Seuri',
'Megeitsu', and 'Doitsu'. Highest fire blight susceptibility in 1988 was found
in 'Okusankichi', '20th Century' and 'Seigyoku'. With respect to the rootstock
those cultivars on Pyrus betulaefolia had a lower USDA fire blight
rating with a larger percentage of tree surface blighted than did the other
three species of rootstock. By 1988, there was little difference with regard
to the percentage of trees flowering as a function of rootstock.
Vega de Rojas, R. and S. Kitto. 1990. Regeneration of Carica pentagona
(Babaco). p. 376. In: J. Janick and J.E. Simon (eds.), Advances in new crops.
Timber Press, Portland, OR.
Regeneration of Carica pentagona (Babaco)
Rebeca Vega de Rojas and Sherry Kitto
Babaco (Carica pentagons) is a subtropical tree naive to Ecuador that
produces seedless fruits having a sweet-tart taste. Recent worldwide
availability of babaco is due to mass propagation in vitro. Because there are
only female plants, babaco can not be improved using conventional breeding
techniques. Improvement of babaco may be possible by using issue culture
regeneration/selection techniques. Babaco ovules at various developmental
stages (10 to 150 days old) and peduncle nodal sections (1 cm) were cultured in
order to produce regenerative cultures. Media components consisted of
Murashige and Skoog salts and vitamins supplemented with glutamine (400 mg/l),
sucrose (3-6%, w/v) and washed Difco Bacto agar (0.8%, w/v). Growth regulators
for ovules included BA (0-3 mg/l) and NAA (0-2 mg/l) and for peduncles included
BA (0.5 mg/l) and IAA (2 mg/l). The pH was adjusted to 5.7-5.8 before
autoclaving. Cultures were grown at 23+/-2°C under cool-white fluorescent
lamps (18 hr photoperiod, 60 µ mol m-2 s-1). Ovular callus initiation and
growth was obtained in the dark when ovules were pretreated by chilling
(4°C). Callus cultures transferred every 5 to 6 weeks for a year have
maintained a consistent growth rate. Calluses grown in the light have
developed green areas that have subsequently produced nodular structures. The nodular structures have initiated shoot primordia that develop into shoots when growth regulators are removed. Histological studies have identified two types of calluses that originate either from the nucellus or the integuments. The nucellar callus appears to have more differentiative potential than the integument callus. Also, babaco ovules appear to be normal, vascularized and complete structures. Axillary shoots have been proliferated from peduncle nodal sections.
Vega de Rojas, R. and S. Kitto. 1990. Regeneration of Carica pentagona
(Babaco). p. 376. In: J. Janick and J.E. Simon (eds.), Advances in new crops.
Timber Press, Portland, OR.
Regeneration of Carica pentagona (Babaco)
Rebeca Vega de Rojas and Sherry Kitto
Babaco (Carica pentagons) is a subtropical tree naive to Ecuador that
produces seedless fruits having a sweet-tart taste. Recent worldwide
availability of babaco is due to mass propagation in vitro. Because there are
only female plants, babaco can not be improved using conventional breeding
techniques. Improvement of babaco may be possible by using issue culture
regeneration/selection techniques. Babaco ovules at various developmental
stages (10 to 150 days old) and peduncle nodal sections (1 cm) were cultured in
order to produce regenerative cultures. Media components consisted of
Murashige and Skoog salts and vitamins supplemented with glutamine (400 mg/l),
sucrose (3-6%, w/v) and washed Difco Bacto agar (0.8%, w/v). Growth regulators
for ovules included BA (0-3 mg/l) and NAA (0-2 mg/l) and for peduncles included
BA (0.5 mg/l) and IAA (2 mg/l). The pH was adjusted to 5.7-5.8 before
autoclaving. Cultures were grown at 23±2°C under cool-white fluorescent
lamps (18 hr photoperiod, 60 µ mol m-2 s-1). Ovular callus initiation and
growth was obtained in the dark when ovules were pretreated by chilling
(4°C). Callus cultures transferred every 5 to 6 weeks for a year have
maintained a consistent growth rate. Calluses grown in the light have
developed green areas that have subsequently produced nodular structures. The nodular structures have initiated shoot primordia that develop into shoots when growth regulators are removed. Histological studies have identified two types of calluses that originate either from the nucellus or the integuments. The nucellar callus appears to have more differentiative potential than the integument callus. Also, babaco ovules appear to be normal, vascularized and complete structures. Axillary shoots have been proliferated from peduncle nodal sections.
Last update March 13, 1997
by aw