Micropropagation ofPyrus andCydonia and their responses to Fe-limiting conditions

Abstract

Appropriate micropropagation regimes were determined for four Pyrus species (P. amygdaliformis Vill., P. betulaefolia Bunge, P. calleryana Dcne., and P. communis L.) and Cydonia oblonga L. Shoot multiplication was optimal at 10 or 20/~M N6-benzyladenine and high light intensity (135 #E m-2s-l). Root formation of the Pyrus species was stimulated by exposure of shoots to high levels (10 or 32/~M) of/~-indolebutyric acid (IBA) for 7 days or a dip in 10 mM IBA for 15 s, followed by a passage on auxin-free medium. 0~-Naphthaleneacetic acid was more effective than IBA in stimulating rooting of C. oblonga. The effects of Fe-limiting conditions in vitro were determined by comparing the responses of shoots and rooted plantlets to medium containing FeEDTA or FeSO4, with or without bicarbonate. Symptoms of Fe deficiency were genotypedependent and most severe in the presence of FeSO4 and bicarbonate. Chlorosis was pronounced in Cydonia, absent from P. amygdaliformis and P. communis, and intermediate inP. betulaefolia and P. calleryana, indicating a good correlation between in vitro and field responses. Similar responses were obtained with rooted and unrooted shoots. These findings suggest that in vitro cultures may be used for studies of Fe-chlorosis as well as screening for tolerant rootstocks.

Factors effecting adventitious shoot regeneration from leaf explants of quince (Cydonia oblonga)

“…However, in Rubus, incubation in the dark was not found to enhance shoot regeneration (Fiola et al 1990). Our results indicate that an incubation period of 3 weeks in the dark is necessary for shoot regeneration, which is consistent with the findings of Dolcet-Sanjuan et al (1990).…”

“…is widely used as a rootstock for pear but is highly sensitive to Fe deficiency (Dolcet-Sanjuan et al 1990). Development of rootstocks with superior tolerance to various environmental conditions would be beneficial.…”

Micropropagation of apple (Malus domesticaL. cultivar Douce de Djerba) throughin vitroculture of axillary buds

“…George (1996) showed that the IBA was very much used for in vitro and ex vitro rooting of microshoots of apple tree. Dolcet-Sanjuan et al (1990), Berardi et al (1984) and Reed (1995) proved that the IBA is essential to make a success of the rooting of the various varieties of pyrus. Shibli et al (1997) found that the increase in the concentration of IBA, during the rooting of the pear tree, is accompanied by an increase in the length and number of roots.…”

Ülkemizde ve Dünyada Ayva Islahı Çalışmaları

“…Geleneksel yöntemler ve doku kültürü yöntemi ile kolay çoğaltılması [14,15] Ülkemizde ve dünyada, son yıllarda oluşan talep artışı ve bunun yanı sıra hasat ve depolama kolaylığıyla birlikte pazarda iyi fiyat bulması, ayva üretim alanlarının ve farklı sektörlere yönelik özelliklere sahip yeni ayva çeşit ve anaçlarının artışını da beraberinde getirmektedir. Bu bağlamda, çeşit geliştirme çalışmalarında seleksiyon ve melezleme ıslahı yöntemleri kullanılmakta olup meyve kalitesi (irilik, boğuculuk, sululuk, taş hücre miktarı, parlaklık, pas miktarı), verim, tanen içeriği, hasat önü dökümü, anaçlık değeri ve ateş yanıklığı gibi hastalıklara dayanım vb.…”