Abstract:

It is reported that chromosome 1R of rye (Secale cereale L.) convey phosphorus use efficient gene (s), and 1RS/1BL translocation genotype Lovrin No.10 is P use efficient. So we hypothesized whether P efficient gene(s) locate on 1RS, and the high P efficiency of Lovrin No.10 is from 1RS? To test this hypothesis, we investigated the P use efficiency (PUE) of a doubled haploid (DH) population with 61 lines derived from anther culture of F₁ hybrid between Lovrin No.10 and phosphorus uptake inefficient genotype Chinese Spring to see whether PUE differs between DH line with and without 1RS/1BL translocation. Acidic polyacrylamide-gel electrophoresis (A-PAGE) of gliadin and genomic DNA in situ hybridization (GISH) were employed to discriminate 1RS/1BL translocation DH lines from the normal 1B DH lines. Among the 61 DH lines investigated, A-PAGE analysis showed that 34 lines contained the 1RS/1BL translocation chromosome, which was characterized by the presence of a 1RS-specific Sec-1 marker bands. Further verification with GISH proved that 33 in the 34 lines contained a pair of homozygous 1RS/1BL translocation chromosomes, only one line was a 1RS/1BL monosomic line. A field experiment was carried out on P deficient soil to investigate grain yield, biomass, numbers of spikes per plant (SPP), P uptake efficiency (PUpE), and P utilization efficiency (PUtE) of the DH lines and their parents under -P (nil P applied) and +P (60 kg P/hm² applied) at maturity. Results showed soil P deficiency decreased the values of the first four traits in Lovrin No.10, but were more severe for Chinese Spring. Lovrin No.10 had higher values of all the above tested traits at both -P and +P than Chinese Spring did, but had similar PUtE with Chinese Spring. These five traits segregated, and differed greatly among DH lines under both -P and +P conditions. Although the variations among DH lines exceeded the difference between the two parents, the average values of the DH lines were between the two parents. The average of the above five traits, and P deficiency tolerance (PDT) (measured by relative grain yield of -P/+P) were not different between the DH lines with and without 1RS/1BL translocation. This indicated that there was no association between 1RS and PUE and PDT in Lovrin No.10, and 1RS may not have P efficient gene(s). Therefore, in the offspring of Lovrin No.10, it is possible to combine high PUE and PDT with good quality without the negative effect of 1RS on flour quality.

Key words: phosphorus use efficiency, wheat (Triticum aestivum), DH lines, GISH, A-PAGE, 1RS/1BL