Efficient Rooting System for Apple “M.9” Rootstock Using Rice Seed Coat and Smocked Rice Seed Coat

“M.9” rootstock is considered as one of the most useful apple (Malus x domestica Borkh.) rootstocks; it produces dwarfing trees efficiently. As “M.9” rootstock shows a poor, brittle, and shallow roots system, we grafted “M.9” rootstocks onto “Marubakaidou” (M. prunifolia Borkh. var. ringo Asami Mo 84-A). We then propagated them by mound layering to establish a high-density root system. It was found that covering the roots with rice seed coat (RSC), RSC + smoked rice seed coat (SRSC), and vermiculite during mound layering was effective for the initiation of rooting. Utilizing RSC and SRSC seemed especially effective for producing “M.9” roots efficiently

Several New Aspects of the Foraging Behavior of Osmia cornifrons in an Apple Orchard

We investigated the foraging behavior of Osmia cornifrons Radoszkowski, which is a useful pollinator in apple orchards consisting of only one kind of commercial cultivars such as “Fuji”, and of different types of pollinizers, such as the red petal type, “Maypole” or “Makamik”. It was confirmed that, in terms of the number of foraging flowers per day, visiting flowers during low temperatures, strong wind, and reduced sunshine in an apple orchard, O. cornifrons were superior to honeybees. We indicated that O. cornifrons seemed to use both petals and anthers as foraging indicator, and that not only female, but also males contributed to apple pollination and fertilization by the pollen grains attached to them from visiting flowers, including those at the balloon stage. It was confirmed that O. cornifrons acts as a useful pollinator in an apple orchard consisting of one kind of cultivar with pollinizers planted not more than 10 m from commercial cultivars

Association Mapping and Validation of QTLs for Flour Yield in the Soft Winter Wheat Variety Kitahonami

<div><p>The winter wheat variety Kitahonami shows a superior flour yield in comparison to other Japanese soft wheat varieties. To map the quantitative trait loci (QTL) associated with this trait, association mapping was performed using a panel of lines from Kitahonami’s pedigree, along with leading Japanese varieties and advanced breeding lines. Using a mixed linear model corrected for kernel types and familial relatedness, 62 marker-trait associations for flour yield were identified and classified into 21 QTLs. In eighteen of these, Kitahonami alleles showed positive effects. Pedigree analysis demonstrated that a continuous pyramiding of QTLs had occurred throughout the breeding history of Kitahonami. Linkage analyses using three sets of doubled haploid populations from crosses in which Kitahonami was used as a parent were performed, leading to the validation of five of the eight QTLs tested. Among these, QTLs on chromosomes 3B and 7A showed highly significant and consistent effects across the three populations. This study shows that pedigree-based association mapping using breeding materials can be a useful method for QTL identification at the early stages of breeding programs.</p></div

Relationships between flour yield (FlYd) and flour efficiency (FlEf) (A), FlYd and median diameter of particles (x50) (B) and FlYd and specific surface area of particles (Sv) (C).

<p>Accessions could be classified into either soft or hard kernel types based on <i>Pina-D1</i>/<i>Pinb-D1</i> genotypes. Soft accessions have <i>Pina-D1a</i> and <i>Pinb-D1a</i>, while hard have <i>Pina-D1b</i> or <i>Pinb-D1b</i>.</p

Correlation coefficients among environments for flour yield (FlYd).

<p>Correlation coefficients among environments for flour yield (FlYd).</p

Distributions of p- and q-values and impact of kernel type correction on association mapping results for flour yield (FlYd).

<p>The distribution was calculated without (w/o) or with (w) employing kernel type as a covariant.</p

Scatter diagrams of predicted and actual FlYd values in DH lines.

<p>Regression models were constructed using the three DH populations together (DH_total) (A) or separately (DH_each) (B). KK: Kinuhime/Kitahonami, TK: Tohoku224/Kitahonami, SK: Shunyou/Kitahonami population.</p

PCR assays to detect of polymorphic SNPs between Kitahonami and the three other varieties used as parents in the DH populations.

<p>White and black arrows indicate bands derived from genome-specific and allele-specific amplicons, respectively. 1: Kitahonami, 2: Kinuhime, 3: Tohoku224, 4: Shunyou.</p