Kernel Mass Research Articles

Agronomics and economics of plant population density on processing sweet corn

A detailed analysis of the effect of plant population density (hereafter called ‘populations’) on processing sweet corn is lacking in the peer-reviewed literature. Therefore, field experiments were conducted utilizing six hybrids commonly grown in North America, one of several locations where sweet corn is grown for processing globally. The objectives were to: (1) quantify the effects of population and commercial hybrid on sweet corn growth, development, ear traits, and yield, (2) determine populations for maximum yield for growers and maximum gross profit margin for processors, and (3) compare populations for maximum yield and maximum gross profit margin to populations observed in processing sweet corn fields. Increasing populations from 43,000 to 86,000plantsha−1 linearly increased canopy density, light interception, and length of the vegetative period, while linearly decreasing filled ear length and recovery – the percent of kernel mass represented in green ear mass. The processing hybrids used in this study differed not only in yield potential, ranging from 15.3 to 19.8Mtha−1, but also in their ability to tolerate high populations. In general, higher-yielding hybrids performed best at higher populations. Based on surveys of growers’ fields in North America, populations average 56,000plantsha−1, which was consistent with the average population for maximum gross profit margin for processors ($9900ha−1). Both growers and processors could realize increased yield and profit by using certain hybrids at populations higher than currently used.

The response of rice grain quality to ozone exposure during growth depends on ozone level and genotype

The effects of ozone exposure during the cropping season on rice grain quality were investigated in chamber experiments employing four ozone treatments (charcoal filtered air, ambient, 2× ambient, and 2.5× ambient concentration) and six genotypes. The concentrations of protein and lipids in brown rice increased significantly in response to ozone, while starch concentration and thousand kernel mass decreased. Other parameters, including the concentrations of iron, zinc, phenolics, stickiness and geometrical traits did not exhibit significant treatment effects. Total brown rice yield, protein yield, and iron yield were negatively affected by ozone. Numerous genotypic differences occurred in the response to ozone, indicating the possibility of optimizing the grain quality in high ozone environments by breeding. It is concluded that although the concentrations of two important macronutrients, proteins and lipids, increased in ozone treated grains, the implications for human nutrition are negative due to losses in total grain, protein and iron yield.

The physical and compressive load properties of sunflower (Helianthus annuus L.) fruit

SUMMARY The physical properties and compressive loading of six domestic sunflower hybrids were studied. The mean values of length, width, thickness, geometric diameter, surface area, porosity, single kernel mass, sphericity, bulk and true density, 1000-kernel weight and coefficient of friction were measured at a single level of moisture content. The results for the sunflower seeds showed that the length, width, thickness and geometric diameter dimensions ranged from 9.31-11.52 mm, 4.71-5.92 mm, 2.95-4.87 mm and 5.12-6.31 mm, respectively. The mean sphericity, porosity, static coefficient of friction, bulk and true density ranged from 0.313-0.550, 0.313-0.363, 0.211-0.237, 330.10-449.86 and 502.74-701.21 kg m -3 , respectively. The objective of this study was to evaluate and compare the behavior of six domestic sunflower hybrids (Perun, Bačvanin, Krajišnik, NS-H-111, Pobednik and Šumadinac hybrids) during compressive loading considering the seed moisture content. The seeds of NS-H-111, Šumadinac, Pobednik and Krajišnik demonstrated low values of bio yield force ranging from 29.3 N to 45.2 N when seeds had a low moisture content (between 3.7 and 5.9% w.b.). The opposite occurred for the Bačvanin and Perun hybrids (60.6 N and 76.2 N, respectively) within the same seed moisture content. For all the hybrids, the machine head displacement (deformation) increased as the seed moisture content increased. The linear model shows a decreasing trend of bio yield modulus for all hybrids as the moisture content of seeds increased.

Studies on Some Engineering Properties of Peanut Pod and Kernel

Physical properties viz. dimension (D1, D2, D3), arithmetic mean diameter (AMD), geometric mean diameter (GMD), square mean diameter (SMD), equivalent diameter (EQD), sphericity (Sp) and aspect ratio (AR) of nine different varieties of peanut and its kernel were determined at the moisture content of 4.5±1% db. Dimensions D1,D2,D3 varied between 16.8-34.6, 11.04-14.9, 11.0-14.4 mm for peanut pod, and 11.9-19.8, 8.03-11.65 and 6.82-9.96 mm for peanut kernel, respectively. AMD, GMD, SMD and EQD were 15.9-21.2, 14.6-19.4, 26.1-34.9 and 18.9-25.2 mm for peanut pod and 8.9-13.5, 8.7-12.8, 15.2-22.8 and 10.9-16.4 mm for peanut kernel, respectively. Sp and AR ranged between 0.6-0.7 and 0.4-0.7 for peanut pod and its kernel, respectively. Bulk density for peanut pod and its kernel were 199-329 and 443-619 g/ml, respectively. Thousand kernel mass of nine varieties studied were lowest for M4 (158 g) and highest for IC2 (1594 g) for peanut pod, and lowest for S1 (446 g) and highest for IC2 (784)

The effects of kernel mass and nutrition reward on seed dispersal of three tree species by small rodents

In the present study, colored tags were fastened to individual seeds to investigate seed dispersal and seed fates of Pinus koraiensis, Corylus mandshurica, and Corylus heterophylla with different seed traits. Our aim was to determine the role of the proportion of kernel mass, caloric reward per seed, and tag color in affecting seed removal rates and seed fates. We predicted that higher proportion of kernel mass and caloric reward will favor seed removal and caching, while lower ones will facilitate seed consumption either in situ or after removal. Our results showed that the proportion of kernel mass, rather than seed size, played an important role in determining seed removal rates and seed fates. Seeds of C. heterophylla with the lowest proportion of kernel mass, regardless of their largest size and/or mass, had lower removal rates, lower level of caching but higher proportion of consumption in situ compared with P. koraiensis and C. mandshurica seeds. Seeds with higher caloric reward exhibited greater dispersal distances. Seed kernel proportion was closely correlated to seed removal rates and caching rates, while seed size and hull thickness seemed to play less important role in affecting seed dispersal, probably because the higher seed handling ability of small rodents in the experimental areas. Our investigation revealed no significant effect of tag color on seed removal rates and seed fates of the three seed species.

Determining Weight and Moisture Properties of Sound and Fusarium‐Damaged Single Wheat Kernels by Near‐Infrared Spectroscopy

ABSTRACTSingle kernel moisture content (MC) is important in the measurement of other quality traits in single kernels because many traits are expressed on a dry weight basis. MC also affects viability, storage quality, and price. Also, if near‐infrared (NIR) spectroscopy is used to measure grain traits, the influence of water must be accounted for because water is a strong absorber throughout the NIR region. The feasibility of measurement of MC, fresh weight, dry weight, and water mass of single wheat kernels with or without Fusarium damage was investigated using two wheat cultivars with three visually selected classes of kernels with Fusarium damage and a range of MC. Calibration models were developed either from all kernel classes or from only undamaged kernels of one cultivar that were then validated using all spectra of the other cultivar. A calibration model developed for MC when using all kernels from the wheat cultivar Jagalene had a coefficient of determination (R2) of 0.77 and standard error of cross validation (SECV) of 1.03%. This model predicted the MC of the wheat cultivar 2137 with R2 of 0.81 and a standard error of prediction (SEP) of 1.02% and RPD of 2.2. Calibration models developed using all kernels from both cultivars predicted MC, fresh weight, dry weight, or water mass in kernels better than models that used only undamaged kernels from both cultivars. Single kernel water mass was more accurately estimated using the actual fresh weight of kernels and MC predicted by calibrations that used all kernels or undamaged kernels. The necessity for evaluating and expressing constituent levels in single kernels on a mass/kernel basis rather than a percentage basis was elaborated. The need to overcome the effects of kernel size and water mass on single kernel spectra before using in calibration model development was also highlighted.

Environment and Hybrid Influences on Food‐Grade Sorghum Grain Yield and Hardness

Few studies have examined grain quality of food‐grade sorghum hybrids. The objective of this study was to determine the effects of environment and hybrid on grain quality of commercially available food‐grade sorghums. A randomized complete block experiment with three replications was planted in 12 environments, which included the 2004 and 2005 growing seasons and irrigated and dryland water regimes in eastern, central, and west central Nebraska and a dryland low‐N environment in eastern Nebraska. Environment accounted for 5 to 140 times greater variation in measured parameters than hybrid, and the hybrid × environment interaction accounted for less than 2% of the total variation. Grain yield and kernel mass varied, with low yields of 1.4 Mg ha−1 and kernels weighing 9.5 g 1000 kernels−1 in the low‐N 2004 environment, high grain yields of 10.5 Mg ha−1 under irrigated conditions in central Nebraska in 2005, and kernels weighing 27.8 g 1000 kernels−1 in the eastern Nebraska dryland 2005 environment. Harder grain was produced in 2005 than in 2004, with the west central and central 2005 environments having the lowest tangential abrasive dehulling device (TADD) removals of 14%. Non‐food‐grade hybrids produced higher grain yields and kernel mass than food‐grade hybrids. Grain hardness was greater for non‐food‐grade and medium maturity hybrids when environmental means were lower (i.e., softer) but showed little or no difference in hardness when environmental means were high. Nebraska production environments have the capability to produce high quality food‐grade sorghums for specific food uses to benefit both the producer and the food processor.

Physiological Effects of Late Season Glyphosate Applications on Peanut (Arachis hypogaea) Seed Development and Germination

Abstract Field studies were conducted to determine runner type peanut response to glyphosate at 80, 160, 240, 320, and 470 g ae/ha applied 75, 90, and 105 days after planting (DAP) at Plains and Ty Ty Georgia in 2006 and 2007. Data collected included seed kernel mass, peanut pod yield, and seed germination. The two-way interaction between DAP and glyphosate rate was not observed for any variable. Data indicated that glyphosate applied at 75 DAP reduced peanut seed mass to 643 mg/kernel, which was less than the 90 or 105 DAP application masses of 669 and 665 mg/kernel, respectively. This could be attributed to the timing of that application when peanut was in the beginning of pod fill or R3 growth stage of development. Peanut physiological response to glyphosate was reflected in peanut seed mass. As glyphosate dose increased, peanut seed mass decreased. Seed masses following glyphosate at 80, 160, 240, 320, or 470 g/ha were 669, 674, 662, 645, and 625 mg/kernel, respectively, as compared to 678 mg/kernel for the nontreated control. When glyphosate was applied at 80 or 160 g/ha, peanut pod yield was similar to the nontreated control. At glyphosate rates of 240, 320, and 470 g/ha, peanut pod yield was reduced to 88, 76, and 64% of the nontreated control. Peanut pod yield was reflective of the reductions in seed mass with increasing glyphosate rate which reduced yield. Seed germination was 96% and greater, which indicated that glyphosate applied at any rate or timing did not affect viability compared to the nontreated control.

Groat proportion in oats as measured by different methods: Analysis of oats resistant to dehulling and sources of error in mechanical dehulling

Groat proportion is the groat yield from an oat dehulling process. We compared hand, impact and compressed-air dehulling to measure groat proportion, and evaluated sources of error. Hand dehulling was the simplest and most accurate method, because all groats and hulls can be accounted for. Mechanical methods dehulled most, but not all, oat kernels. Failure to account for oats resistant to dehulling in calculations resulted in gross errors. Oats resistant to impact dehulling did not differ in groat proportion from the general population, but differed in many physical properties. Hull structure may account the most for their resistance to dehulling. Mechanically dehulled oats consistently yielded lower groat proportions than those from hand dehulling. Since the difference cannot be attributed to oats resistant to dehulling, groats must be lost during the aspiration process, common to all mechanical methods. Uniform aspiration protocols should provide a uniform error. All groat proportion values obtained here were highly correlated among themselves, except when values were not corrected for oats resistant to dehulling. A theoretical groat proportion calculated from the ratio of the mean groat mass (collected by any means available) and the mean kernel mass yielded a groat proportion value that did not differ significantly from the hand dehulling value.Key words: Oat milling, groat proportion, oat dehulling

Correlation Between Aflatoxin Contamination and Various USDA Grade Categories of Shelled Almonds

The California almond industry is interested in determining if there is a correlation between aflatoxin contamination and almonds classified into various U.S. Department of Agriculture (USDA) grades. A 12 000 g sample was taken from each of 50 lots of shelled almonds. The almonds in each sample were then partitioned into five USDA grades: high quality (HQ), insect damage (ID), mold damage (MOD), mechanical damage (MED), and other defects (OD). Across all 50 samples, kernels in the HQ grade accounted for 83.7% of the kernel mass and 3.2% of the aflatoxin mass. Conversely, kernels in the remaining four damage grades (ID, MOD, MED, and OD) accounted for 16.3% of the kernel mass and 96.8% of the aflatoxin mass. ID kernels had the highest risk for aflatoxin contamination. Almonds in the ID grade accounted for 76.3% of the total aflatoxin mass and 7.2% of the kernel mass. Regression equations were developed to predict the aflatoxin concentration in each 12 000 g sample by measuring the aflatoxin mass in one or more of the four damage grades. Regression equations demonstrated that aflatoxin mass only in the insect damaged kernels was also an effective way to predict the aflatoxin concentration in each 12 000 g sample.

Fruit production under different environmental and management conditions of argan, Argania spinosa (L.)

Abstract The study’s aim was to evaluate the effects of different management and environmental conditions on fruit and seed mass production of Argania spinosa , an endemic tree to Morocco that grows in arid and semiarid areas and is now undergoing a protracted regression due to overexploitation. Four study areas with different herbivory intensity, altitude and climatic conditions were selected. In each one the following measurements were carried out in 20 trees: tree and crown height, crown projection, trunk diameter, leaf area index, tree density, fruit production·m −3 , number of fruits per tree, fruit, endocarp and kernel mass and seed size. The greatest fruit production and fruit size were found in populations with better climatic conditions, followed by the population under high human pressure. The lowest fruit production and fruit size were found in the population under the most severe climate conditions. Mean kernel mass was not affected by harsh climatic conditions or high human pressure, but when both stressing factors were combined all measured fruit traits were abated. Although A. spinosa is tolerant to high herbivory pressure, this perturbation induces a drastic decrease in fruit production. Managing plans addressing its reintroduction and/or maintenance should include a conservative strategy controlling herbivory.

Sugar Levels Regulate Tryptophan-Dependent Auxin Biosynthesis in Developing Maize Kernels

The maize (Zea mays) Miniature1 (Mn1) locus encodes the cell wall invertase INCW2, which is localized predominantly in the basal endosperm transfer layer of developing kernels and catalyzes the conversion of sucrose into glucose and fructose. Mutations in Mn1 result in pleiotropic changes, including a reduction in kernel mass and a recently reported decrease in indole-3-acetic acid (IAA) levels throughout kernel development. Here, we show that mn1-1 basal kernel regions (pedicels and basal endosperm transfer layer) accumulate higher levels of sucrose and lower levels of glucose and fructose between 8 and 28 d after pollination when compared with the wild type, whereas upper regions of mn1 accumulate similar or increased concentrations of sugars. To determine the cause of the reduction in IAA accumulation, we investigated transcript levels of several potential IAA biosynthetic enzymes. We demonstrate that reduced IAA levels most closely correspond to reduced transcript levels of ZmYUCCA (ZmYUC), a newly identified homolog of the Arabidopsis (Arabidopsis thaliana) gene YUCCA. We further demonstrate that ZmYUC catalyzes the N-hydroxylation of tryptamine and that sugar levels regulate transcript levels of ZmYUC, both in in vitro-cultured kernels and in a promoter-reporter fusion in Arabidopsis. These results indicate that developing seeds may modulate growth by altering auxin biosynthesis in response to sugar concentrations.

Estimation of Mass Ratio of the Total Kernels within a Sample of In‐Shell Peanuts Using RF Impedance Method

It would be useful to know the total kernel mass within a given mass of peanuts (mass ratio) while the peanuts are bought or being processed. In this work, the possibility of finding the mass ratio while the peanuts were in their shells was investigated. Capacitance, phase angle, and dissipation factor measurements on a parallel‐plate capacitor holding in‐shell peanut samples were made at frequencies from 1 to 10 MHz insteps of 1 MHz. A calibration equation was developed by multilinear regression analysis correlating the percentage ratio of the kernel weight with the measured capacitance, dissipation factor, and phase angle values of in‐shell peanut samples with known kernel weights. The equation was used to predict the percentage mass ratio in the validation groups. Fitness of calibration model was verified using standard error of calibration, root mean square error of calibration, and leverage and influence plots. The predictability percentage, within 1% and 2% of the visual determination, was calculated by comparing the kernel mass ratio, obtained by the model equation and the reference value obtained by visual determination. Cross‐validation gave 96% and 100% predictability, and external validation gave 87% and 98% predictability within 1% and 2% difference, respectively.

Source - sink balance and manipulating sink - source relations of wheat indicate that the yield potential of wheat is sink-limited in high-rainfall zones

Grain yield depends on the number of grains per unit area (sink) and the availability of assimilates (source) to fill these grains. The aim of the current work was to determine whether wheat yield in the high-rainfall zone of south-western Australia is limited in current cultivars by the size of the sink or by the assimilates available for grain filling. Three wheat cultivars (Calingiri, Chara and Wyalkatchem) and two breeding lines (HRZ216 and HRZ203) were grown in four replicates in the field from 2005 to 2007. Dry matter and water soluble carbohydrates (WSC) at anthesis and maturity were measured and used to determine the source and sink balance of the crop. In 2007, three further treatments were applied to manipulate the sink–source relationships: (i) spikelets were removed on main stems to increase the source : sink ratio; (ii) incoming solar radiation was reduced by 40% by shading after anthesis to reduce the availability of assimilates to grains; and (iii) supplemental irrigation was used to maintain the capacity for photosynthesis by an improved water supply during grain filling. The source–sink balance of the crops showed that the potential source was 25% greater than the actual grain yield in average and above-average seasons (2005 and 2007), suggesting that sink size, represented by the number of grain per unit area, was a limiting factor to yield potential. However, the source may have become a limiting factor in a drought season (2006). The grain yield increased with increased number of grains/m2 and kernel weight remained relatively stable even when grain number increased from 7000 to 16 000 per m2. The removal of half of the spikelets on the main stem did not increase kernel mass of the remaining grains and an additional 33 mm of irrigation water did not increase grain yield, but significantly (P < 0.05) increased WSC left in stems and leaf sheaths at maturity. Shading after anthesis did not significantly reduce grain yield of the current cultivars Calingiri and Wyalkatchem, but it reduced grain yield by 23–25% (P < 0.05) in Chara and HRZ203. The source–sink balance over three seasons and three independent experiments in 2007 suggested that the yield of the current wheat cultivars is more sink- than source-limited and that breeding wheat with a larger sink size than in the current cultivars may lift the yield potential of wheat in the high-rainfall zone of south-western Australia.

NUTRITIONAL QUALITY OF Jatropha curcas SEEDS AND EFFECT OF SOME BIOLOGICAL AND CHEMICAL TREATMENTS ON THEIR ANTINUTRITIONAL FACTORS

The physical characteristics of Egyptian Jatropha curcas seeds were studied. The average of whole seed mass, kernel weight, shell weight, percentage kernel mass of whole seeds and percentage shell mass of whole seeds were 0.69, 0.47, 0.22, 68.12 g and 31.88% respectively. Chemical composition proved that J. curcas seeds are a good source of protein (32.88%), oil (27.36%) and carbohydrates (30.11%). The seeds are rich in various micro-elements, that is Mn, Fe, and Zn which recorded 28.37, 0.38 and 47.13 mg/kg, respectively as well as macro-elements, that is, K, Ca, Na, Mg and P, which recorded 103.13, 34.21, 8.44, 109.89 and 185.17 mg/kg respectively. The seeds contain 52.59 mg/100 g, 25.58 mg/g, 39.95 mg/100 g and 1.51 g/100 g of phytic acid, trypsin inhibitor activity, total phenols and saponins, respectively. Therefore, it could be inferred that the seeds is nutritionally promising because of its high nutrient content and low antinutrient level. The effect of some physical treatments (soaking, germination and roasting) and some chemical treatments (NaHCO3, ethanol extraction and NaOH) were successful inactivating the antinutrients.

Molecular line profiles of collapsing gas clouds

Emission line profiles of tracer molecule H$_2$CO 140 GHz transition from gravitational core collapsing clouds in the dynamic process of forming protostars are calculated, using a simple ray-tracing radiative transfer model. Three self-similar dynamic inside-out core collapse models -- the conventional polytropic model, the empirical hybrid model and the isothermal model -- for star-forming molecular clouds are examined and compared. The isothermal model cannot produce observed asymmetric double-peak molecular line profiles. The conventional polytropic model, which gives flow velocity, mass density and temperature profiles self-consistently, can produce asymmetric double-peak line profiles for a core collapsing cloud. In particular, the blue peak is stronger than the red peak, consistent with a broad class of molecular line profile observations. The relative strengths of the blue and red peaks within a molecular line profile are determined by the cloud temperature gradient. The conventional polytropic model can be utilized to produce molecular line-profile templates, for extracting dynamical information from line spectra of molecular globules undergoing a gravitational core collapse. We show a sample fit using the 140 GHz H$_2$CO emission line from the central region of the molecular globule B335 by our model with $\gamma=1.2$. The calculation of line profiles and fitting processes also offer a scenario to estimate the protostellar mass, the kernel mass accretion rate, and the evolution time scale of a core collapsing cloud. Our model can be readily adapted to other tracer molecules with more or less constant abundances in star-forming clouds.

KERNEL EXTRACTION AND MACHINE EFFICIENCY IN DEHULLING PARBOILED AFRICAN BREADFRUIT (TRECULIA AFRICANA DECNE) WHOLE SEEDS

ABSTRACT Parboiling and dehulling are two closely associated primary operations preceding African breadfruit (Treculia africana) seed kernel extraction and subsequent utilization in any food form. Three process variable conditions for parboiling the seeds (quantity of parboiled seeds, parboiling temperature and parboiling time) for dehulling and kernel extraction were investigated using a central composite design. The objectives of the research were to maximize kernel and extraction yields and dehulling and machine efficiencies through process variable combinations. Maximum kernel mass (91.33%) was obtained at the center point process combination (12 kg, 80C and 13 min, respectively). Extraction yield and total recovered wastes were 94.08 and 7.31%, while dehulling and machine efficiencies were 72.62 and 96.97%, respectively. Models developed by response surface analysis for these responses ranged from 62 to 93%. Temperature effects on kernel mass, extraction yield and total wastes were both linear and quadratic.PRACTICAL APPLICATIONSDehulling operation, to a great extent, is dependent on parboiling process conditions. This research located the optimum combination of process variables that would lead to maximum kernel yield and machine efficiency using second‐order central composite design and response surface analysis. It also reported the ability of locally fabricated power‐driven commercial attrition mill, designed for grinding cereals and grain‐legumes, to thresh and dehull parboiled African breadfruit whole seeds. Because the seeds are extracted,parboiled and dehulled before their utilization in any food form, information obtained in this research would be needful not only to processors of African breadfruit seeds, but also to those processing grain‐legumes and other seeds requiring dehulling process before conversion into any food form.

Prediction of maize seed attributes using a rapid single kernel near infrared instrument

Non-destructive measurements of seed attributes would significantly enhance breeder selection of seeds with specific traits, and could potentially improve hybrid development. A single kernel near infrared reflectance (NIR) instrument was developed for rapidly predicting maize grain attributes, which would enable plant breeders to quickly select promising individual seeds. With the overall goal being to develop spectrometric calibrations, absorbance spectra from 904 to 1685 nm were collected from 87 maize samples, with 30 kernels of each sample (2610 kernels total), representing a wide variability in the essential amino acids tryptophan and lysine, crude protein, oil and soluble sugar contents. Average sample spectra were matched to bulk reference values. Partial least squares regression (PLSR) calibration models with cross-validation were developed for both relative (% dry matter) and absolute (mg kernel −1) constituent contents. Similarly, models using bagging PLSR were developed. The best model obtained was for relative crude protein content, with an R 2p of 0.75 and a SEP of 0.47%. Kernel mass was also highly predictable ( R 2p=0.76, SEP=0.03 g). Tryptophan, lysine and oil were less predictable, but showed good potential for segregating individual seeds using NIR. Soluble sugar contents produced poor model statistics. Bagging PLSR yielded models with similar levels of prediction.

Fractionation of transgenic corn seed by dry and wet milling to recover recombinant collagen‐related proteins

Corn continues to be considered an attractive transgenic host for producing recombinant therapeutic and industrial proteins because of its potential for producing recombinant proteins at large volume and low cost as coproducts of corn seed-based biorefining. Efforts to reduce production costs have been primarily devoted to increasing accumulation level, optimizing protein extraction conditions, and simplifying the purification. In the present work, we evaluated two grain fractionation methods, dry milling and wet milling, to enrich two recombinant collagen-related proteins; thereby, reducing the amount and type of corn-derived impurities in subsequent protein extraction and purification steps. The two proteins were a full-length human recombinant collagen type I alpha 1(rCIalpha1) chain with telopeptides and peptide foldon to effect triple helix formation and a 44-kDa rCIalpha1 fragment. For each, approximately 60% of the rCIalpha1s in the seed was recovered in the dry-milled germ-rich fractions making up ca. 25% of the total kernel mass. For wet milling, approximately 60% of each was recovered in three fractions accounting for 20-25% of the total kernel mass. The rCIalpha1s in the dry-milled germ-rich fractions were enriched three to six times compared with the whole corn kernel, whereas the rCIalpha1s were enriched 4-10 times in selected wet-milled fractions. The recovered starch from wet milling was almost free of rCIalpha1. Therefore, it was possible to generate rCIalpha1-enriched fractions by both dry and wet milling along with rCIalpha1-free starch using wet milling. Because of its simplicity, the dry milling procedure could be accomplished on-farm thus minimizing the risk of inadvertent release of viable transgenic seeds.

Localisation of quantitative trait loci for quality attributes in a doubled haploid population of wheat (Triticum aestivumL.)

Selection of wheat germplasm for a range of quality traits has been a challenging exercise because of the cost of testing, the variation within testing data, and a poor understanding of the underlying genetics. The objective of this study was to identify quantitative trait loci (QTLs) underlying quality traits in wheat. A doubled haploid population comprising 190 lines from Chara/WW2449 was grown in two different environments and evaluated for various quality traits. A molecular map comprising 362 markers based upon simple sequence repeat, sequence tagged microsatellite, glutenin, and DArT loci was constructed and subsequently exploited to identify QTLs using a whole-genome approach. Fifteen QTLs that were consistent in the two different environments were identified for thousand kernel mass, grain protein content, milling yield, flour protein content, flour colour, flour water absorption, dough development time, dough strength (extensograph height and resistance at 5 cm), and dough extensibility (extensograph length) using the whole genome average interval mapping approach. The amount of genetic variation explained by individual QTLs ranged from 3% to 49%. A number of QTLs associated with dough strength, dough extensibility, dough development time, and flour water absorption were located close to the glutenin Glu-B1 locus on chromosome 1B. Identification of the chromosomal location and effect of the QTLs influencing wheat quality may hasten the development of superior wheats for target markets via marker-assisted selection.