Oilseed rape genotypes response to boron toxicity

Abstract

Response of 16 oilseed rape genotypes to B (boron) toxicity was analyzed by comparing the results of two experiments conducted in a glasshouse. In Experiment 1 plants were grown in standard nutrient solutions with 10 µMB (control) and 1000 µM B. Relative root and shoot growth varied from 20-120% and 31-117%, respectively. Variation in B concentration in shoots was also wide (206.5-441.7 µg B g-1 DW) as well as total B uptake by plant (62.3-281.2 µg B g1). Four selected genotypes were grown in Experiment 2 in pots filled with high B soil (8 kg ha-1 B; B8). Shoot growth was not affected by B8 treatment, while root and shoot B concentration was significantly increased compared to control. Genotypes Panther and Pronto which performed low relative root and shoot growth and high B accumulation in plants in Experiment 1, had good growth in B8 treatment. In Experiment 2 genotype NS-L-7 had significantly lower B concentration in shots under treatment B8, but also very high B accumulation in Experiment 1. In addition, cluster analyses classified genotypes in three groups according to traits contrasting in their significance for analyzing response to B toxicity. The first group included four varieties based on their shared characteristics that have small value for the relative growth of roots and shoots and large values of B concentration in shoot. In the second largest group were connected ten genotypes that are heterogeneous in traits and do not stand out on any characteristic. Genotypes NS-L-7 and Navajo were separated in the third group because they had big relative growth of root and shoot, but also a high concentration of B in the shoot, and high total B uptake. Results showed that none of tested genotypes could not be recommended for breeding process to tolerance for B toxicity.

Izvod Odgovor 16 genotipova uljane repice na toksičnost B (bora) analizirana je poređenjem rezultata dva ogleda izvedenim u stakleniku. U Ogledu 1, biljke su gajene u hranljivim rastvorima sa dva tretmana B: 10 µM B (kontrola) i 1000 µM B (toksična koncentracija). Vrednosti za relativni porast korena i nadzemnog dela varirale su od 20-120% i 31-117%, po redu. Koncentracija B je takođe značajno varirala (206.5-441.7 µg B g-1 SM) kao i ukupno usvojena količina B po biljci. Na osnovu rezultata dobijenih u Ogledu 1 odabrana su četiri genotipa koja su u Ogledu 2 gajena u posudama sa zemljištem kome je dodat B preračunato za poljske uslove u količini od 8 kg ha-1 (B8) uz kontrolu..Toksične količine B nisu negativno uticale na porast biljaka, dok je koncentracija B u korenu i nadzemnoj masi značajno povećana u poređenju sa kontrolom. Iako su u Ogledu 1 zabeležene velike razlike u porastu biljaka i koncentraciji B u suvoj masi, rezultati dobijeni u Ogledu 2, nisu pokazali da je kod bilo kog genotipa prisutna tipična reakcija na osnovu koje bi bili svrstani u grupu osetljivih ili tolerantnih na tiksičnost B. Genotipovi Panther i Pronto kod kojih je u Ogledu 1 zabeležen mali relativni porast korena i nadzemnog dela, kao i velika koncentracija B u biljci, imali su dobar porast u tretmanu sa 8 kg ha-1. U Ogledu 2, kod genotipa NS-L-7 zabeležena je značajno niža koncnetracija B u nadzemnom delu biljaka, ali i velika akumulacija B u Ogledu 1. Kluster analizom genotipovi su podeljeni u tri grupe na osnovu relativnog porasta korena i nadzemnog dela, koncentracije B u njima i ukupnom usvajanju B po biljci, ali tako da ne ukazuju na eventualno postojanje otpornosti na toksičnost B. Istraživanje je pokazalo da ni jedan od 16 testiranih genotipova ne može da bude preporučen za proces oplemenjivanja za otpornost na toksičnost B.