The primary objective of the present study is the characterization of the hybrids of dikaryon-monokaryon(di-mono) and monokaryon-monokaryon(mono-mono) crosses in mushroom breeding. We employed this technique for developing develop superior species from Pleurotus spp. varieties with 56 Di-mono intraspecific hybrids of 14 combinations and 85 mono-mono intraspecific hybrids of 7 combinations between six Pleurotus ostreatus varieties and one Pleurotus florida variety. In this study, the results of analysis on hybridization rate, nuclear and mitochondrial DNA patterns, and colors and yields of fruit-bodies, are presented as follows. In di-mono crosses, hybrids between Pleurotus ostreatus and Pleurotus florida showed 100% of crossability as seen in those between Pleurotus ostreatus and Pleurotus ostreatus indicating that nuclei and mitochondria of a dikaryon migrated to a recipient of monokaryon. The mitochondrial DNA patterns of the hybrid strain were composed of 75% dikaryon donors and 25% monokaryon recipient. The crossability between mono-mono crossing ranges between 50 and 93.75%. 82.4% of the hybrid strain showed mitochondrial DNA patterns predominated by either parent, while the remaining 17.6% had recombinant or half-and-half combined patterns of both parents.

The primary objective of the present study is the characterization of the somatic hybrids of dikaryon-monokaryon (di-mono) crosses in mushroom breeding. We employed this technique for developing superior strain from Pleurotus ostreatus strains with 56 intraspecific hybrids of 14 combinations between six Pleurotus ostreatus strains and one Pleurotus florida strain. In this study, the results of analysis on hybridization rate, nuclear DNA patterns, and colors and morphology of fruit-bodies, are presented as follows. In di-mono crosses, somatic hybrids among Pleurotus strains showed 100% of crossability as seen in those among Pleurotus strains indicating that nuclei of a dikaryon migrated to a recipient. 89.3% of the somatic hybrids among Pleurotus strains were similar to the donor dikaryons, and 10.7% had combined DNA patterns of both parents. In the 14.3% di-mono cross between P. ostreatus and P. florida, the nuclear DNA patterns of the all hybrid strain showed the same or similar patterns compared to the donor dikaryons. 75.0% of the hybrid between P. ostreatus and P. ostreatus were similar to the donor dikaryons; 10.7% had combined DNA patterns of both parents. 82.2% of fruiting body morphology of the hybrids among Pleurotus strains were similar to the dikaryons, and 17.8% had combined DNA patterns of both parents. All hybrid strains between dikaryon P. florida and monokaryon P. ostreatus showed the fruiting body whose colors were similar to those of the dikaryon, while the hybrids between dikaryon P. ostreatus and monokaryon P. florida were all showed combined colors of both parents but are more similar to the dikaryon. Therefore, the fruiting body color of P. florida tends to be generally dominant. The present study was able to find out and suggest superior hybrid strains by identifying the nuclear DNA patterns of hybrids between Pleurotus strains as well as the characteristics of their fruiting bodies. This study expects that the advantages of the di-mono crossing are needs to be fully utilized in mushroom breeding and it is better to develop superior strains of Pleurotus strains.

This study was conducted to develop superior hybrids of Pleurotus ostreatus with di-mono and mono-monoka-ryon crosses. Random Amplified Polymorphic DNA-PCR (RAPD-PCR) was used to compare its mitochondrial DNA profiles of hybrids using specific primers designed from microsatellite markers of Pleurotus salmoneo-stramineus. A total of fifty-six dikaryon-monokaryon hybrids were sampled for RAPD-PCR experiments and the results show that twenty-four hybrids were dikaryon and thirty-one hybrids were monokaryon. Interestingly, one hybrid was an intermediate form with the DNA profiles that are different from those of its parents. The DNA profiles from eighty-eight monokaryon-monokaryon hybrids were also analyzed by RAPD-PCR. The results of mitochondria DNA profiles show that seventy-one hybrids are the same to one of their parents, but seventeen hybrids show DNA profiles of both parents.

Predicate-as Parentheticals exhibit word order variability that interacts with contrastive focus placement on the subject or an adjunct phrase. While Culicover and Winkler (2008) discuss that as-clauses share certain properties with other focus inversion construc- tions, a concrete syntactic analysis of Predicate-as clauses has not been provided in the previous studies in order to explain such word order variations as the auxiliary verb cluster phenomenon. This paper proposes that the complicated word order patterns in Predicate-as clauses be accounted for in terms of a constructional constraint for a focus inversion clause, without changing the basic syntactic and semantic analyses of As-Parentheticals. In our analysis, the focus-inversion-clause construction imposes a constraint on the word order domain, so that word order variability needs not to be directly reflected on the constituent structure of the clause.