Plant breeding for organic and sustainable, low-input agriculture

Agronomic properties of triticale (x Triticosecale wittmack) selected for tolerance to
nutrition deficiency under laboratory conditions.
Danuta Rzepka-Plevneš 1 , Marta Stępień-Słodkowska 2
1 Agricultural University of Szczecin, Poland; 2 University of Szczecin, Poland
Mineral nutrient that are taken up by plant roots are essential for plant growth and crop
production. The macronutrients nitrogen, phosphorus and potassium are frequently added to soil
where crops are grown, because they contain either deficit or suboptimal levels of these nutrients
(Marschner 1995, Shin et al. 2005).
The studies were conducted over the years 2001-2002 and covered 26 varieties of triticale
examined for tolerance to nitrogen and potassium deficiency under in vitro cultures of mature
embryos. The selection of tolerant and partially tolerant seedlings was performed 10 days after
the growth initiation of triticale embryos on a MS medium containing 0.333 mM ⋅ dm -3 nitrogen,
0.225 mM ⋅ dm -3 phosphorus and 0.332 mM ⋅ dm -3 potassium. The MS medium with a full NPK
composition (N - 6.003 mM ⋅ dm -3 , P - 0.125 mM ⋅ dm -3 , K - 2.005 mM ⋅ dm -3 ) comprised the
control medium. Seedlings longer than 5 cm with two well formed leaves and well branched
seminal roots were classified as tolerant, with reduced height to 2.5 cm and developed roots - as
partially tolerant to nitrogen and potassium deficiency. Seedlings tolerant and partially tolerant
were planted into pit pots and after hardening in a glass-house, moved on 0.5 m 2 plots in the field
experiment. The experiment was based on random blocks in three repeats in soil containing in a
100 g of 0.11% total nitrogen, 12 mg P2O5 and 12 mg K2O. During the whole vegetation period
no additional mineral fertilisation was applied. The control seeds of all tested triticale varieties
were obtained from the breeders. The triticale properties were determined at the stage of full
maturity – crop components from an area unit. The obtained results were evaluated statistically.
The results obtained show that tolerant and partially tolerant seedlings, identified by way of
selection at the stage of a mature plant, did not differ from the control plants as regards many of
the properties examined. Some of them proved even superior as regards height, ear length,
number of spikelets in ear, tillering, number of grains per plant and per ear. For most of the
studied features, a significant correlation was observed, both in the tolerant forms and in the
control forms. Special attention should be paid to two triticale varieties that in the in vitro test
were described as partially tolerant (Bogo and Chrono) as well as eight varieties identified as
susceptible (Lasko, Malno, Marko, Moreno, Mundo, Nemo, Prego, Pronto). The results obtained
indicate that from Polish triticale varieties it is possible to select source material for breeding of
varieties for extensive conditions of cultivation.
38