Kernel morphology and texture influence the value of wheat (Triticum aestivum L.). The objectives of this study were to determine associations between kernel traits and molecular markers and to identify quantitative trait loci (QTLs) affecting kernel traits in a soft × hard white wheat cross. Seventy eight F~-derived recombinant inbred lines (RILs) from cross be tween the so ft wh ite wh eat NY 6432-18 (NY18) and the hard white wheat 'Clark's Cream' (CC) were developed by single seed descent. Kernel texture was measured by near infrared reflectance (NIR) on RIL grain samples from six environments. Digital image analysis (DIA) was used to measure kernel length, width, area, perimeter on grain samples from four environments. Test weight and thousand kernel weight (TKW) were also determined. Shape factor and density factor were calculated. The map for this population consisted of 313 molecular markers in 47 linkage groups located on all wheat homoeologous chromosome groups. Linkage groups that mapped to wheat homoeologous group 2 chromosomes were highly skewed towards NY18 alleles. Genotype effects and genotype × environment interactions were highly significant for most traits. QTLs for kernel width and kernel length also influenced kernel area and TKW, but did not influence each other. The pinB marker at the puroindoline B locus on chromosome 5DS explained over 60% of the phenotypic variation for kernel texture. QTLs for kernel traits were located on chromosomes IA, 2B, 2D, 3B, 7A, and 7B. Tm HE ECONOMIC VALUE of the U.S. wheat crop is deterined by class, which depends in part on kernel morphology and texture, and by test weight. Inspectors for the U.S. Grain Inspection, Packers and Stockyards Administration use color, shape, and length of the kernel and shape of the germ, crease, and brush to determine wheat grain classes (GIPSA, 1997). In general, hard wheat kernels are long, narrow, and translucent while soft kernels are short, rounded, and chalky in appearance. Hybridization between classes reduces the correlation between kernel morphology and wheat class and reduces the accuracy of the current classification

Interclass hybridization between soft and hard wheat (Triticum aestivum L.) results in new genetic combinations of potential value. We investigated whether interclass hybridization could improve end‐use quality of both classes. Our objectives were to analyze quality traits in a population of recombinant inbred lines (RILs) derived from a cross between the good quality soft white wheat NY6432‐18 (NY18), and good quality hard white wheat Clark's Cream (CC), identify quantitative trait loci (QTLs) for those traits, and use linkage analysis to determine which parent was contributing favorable alleles at specific QTLs for a given trait. The population was assessed for milling, protein and dough mixing, hydration, cookie and loaf traits. Traits were measured in two to six environments grown over three seasons in Ithaca, NY. The molecular map for the population contains 370 molecular markers including restiction fragment length polymorphisms (RFLPs), microsatellites, and markers derived from known function genes in wheat. Linkage groups have been located to all the wheat chromosomes except for 7D. Pinb derived from the puroindoline b gene on chromosome 5DS was the major QTL for milling, hydration, and cookie baking traits. The major QTL for mixograph peak time was at the Glu‐Dy1 marker, derived from Glu‐D1‐2 gene on chromosome 1DL. The Glu‐Ax1 and Glu‐By1 markers were QTLs for mixograph peak height and tolerance, respectively. QTLs for flour protein quantity were detected on chromosome 2B. With the exception of the hydration traits, multiple regression models included alleles from both parents. Interclass hybridization may be an underexploited wheat breeding strategy for improvement of agronomic and quality traits in wheat.

Penetration of a male copulatory organ into a suitable mate is a conserved and necessary behavioral step for most terrestrial matings; however, the detailed molecular and cellular mechanisms for this distinct social interaction have not been elucidated in any animal. During mating, the Caenorhabditis elegans male cloaca is maintained over the hermaphrodite's vulva as he attempts to insert his copulatory spicules. Rhythmic spicule thrusts cease when insertion is sensed. Circuit components consisting of sensory/motor neurons and sex muscles for these steps have been previously identified, but it was unclear how their outputs are integrated to generate a coordinated behavior pattern. Here, we show that cholinergic signaling between the cloacal sensory/motor neurons and the posterior sex muscles sustains genital contact between the sexes. Simultaneously, via gap junctions, signaling from these muscles is transmitted to the spicule muscles, thus coupling repeated spicule thrusts with vulval contact. To transit from rhythmic to sustained muscle contraction during penetration, the SPC sensory-motor neurons integrate the signal of spicule's position in the vulva with inputs from the hook and cloacal sensilla. The UNC-103 K+ channel maintains a high excitability threshold in the circuit, so that sustained spicule muscle contraction is not stimulated by fewer inputs. We demonstrate that coordination of sensory inputs and motor outputs used to initiate, maintain, self-monitor, and complete an innate behavior is accomplished via the coupling of a few circuit components.

Milling and baking quality traits in wheat (Triticum aestivum L.) were studied by QTL analysis in the ITMI population, a set of 114 recombinant inbred lines (RILs) generated from a synthetic-hexaploid (W7985) x bread-wheat (Opata 85) cross. Grain from RILs grown in U.S., French, and Mexican wheat-growing regions was assayed for kernel-texture traits, protein concentration and quality, and dough strength and mixing traits. Only kernel-texture traits showed similar genetic control in all environments, with Opata ha alleles at the hardness locus Ha on chromosome arm 5DS increasing grain hardness, alkaline water retention capacity, and flour yield. Dough strength was most strongly influenced by Opata alleles at 5DS loci near or identical to Ha. Grain protein concentration was associated not with high-molecular-weight glutenin loci but most consistently with the Gli-D2 gliadin locus on chromosome arm 6DS. In Mexican-grown material, a 2DS locus near photoperiod-sensitivity gene Ppd1 accounted for 25% of variation in protein, with the ppd1-coupled allele associated with higher (1.1%) protein concentration. Mixogram traits showed most influence from chromosomal regions containing gliadin or low-molecular-weight glutenin loci on chromosome arms 1AS, 1BS, and 6DS, with the synthetic hexaploid contributing favorable alleles. Some RI lines showed quality values consistently superior to those of the parental material, suggesting the potential of further evaluating new combinations of alleles from diploid and tetraploid relatives, especially alleles of known storage proteins, for improvement of quality traits in wheat cultivars