Growth, flowering and leaf properties of pear cultivars grafted on two Asian pear rootstock seedlings under NaCl irrigation

The growth responses of grafted young pear trees under salinity were studie d. Chinese, Japanese and European pear cultivars (Yari, Kosui and La France ) were grafted onto 3-year-old Pyrus betulifolia Bunge (BET) and P. pyrifol ia (Burm f.) Nakai (PYR) seedlings. They were grown in pots with sand and i rrigated with 20% Hoagland's plus 0, 25 or 50 mM NaCl solution. All scions grafted onto BET grew well even under 50 mM NaCl irrigation, while those gr afted onto PYR suffered from NaCl deficiency heavily. Flower bud formation was stimulated by NaCl treatment in every scion-rootstock combination. Bloo m date and number of flowers per cluster were not affected by NaCl treatmen t. Mineral analysis suggested that BET's salt tolerance is due to the abili ty of this cultivar to restrict Na and Cl ion transport to leaves. (C) 2000 Elsevier Science B.V. All rights reserved.