milliliters of water can enter a single fruit, and the fruit's internal cells are not protected from attack. This water absorption is driven by principles described in the general gas law ( Showalter and Bartz, 1979 ). Changes in the pressure of an ideal gas
S.M. Smith, J.W. Scott, J.A. Bartz, and S.A. Sargent
Frank M. Elia, George L. Hosfield, James D. Kelly, and Mark A. Uebersax
A knowledge of the relative proportion of additive and nonadditive genetic variances for complex traits in a population forms a basis for studying trait inheritance and can be used as a tool in plant breeding. A North Carolina Design II mating scheme was used to determine the inheritance of cooking time, protein and tannin content, and water absorption among 16 genotypes of dry bean (Phaseolus vulgaris L.) representative of the Andean Center of Domestication. Heritability and the degree of dominance for the traits were also calculated to provide guidelines for adopting breeding strategies for cultivar development. Thirty-two progeny resulted from the matings and these were assigned to two sets of 16 progeny each. Variances due to general combining ability (GCA) and specific combining ability (SCA) were significant for the traits. The GCA was larger in all cases. Narrow-sense heritability for protein, tannin, water absorption, and cooking time averaged 0.88, 0.91, 0.77, and 0.90, respectively. Degree of dominance estimates indicted that the traits were governed by genes with partial dominance except, in one case, tannin had a degree of dominance value of zero, indicating no dominance. The phenotypic correlation (-0.82) between water absorption and cooking time justifies using the water absorption trait as an indirect selection method for cooking time. With regard to parent selection in crosses, significant differences between GCA females and GCA males suggested cytoplasmic influences on trait expression. Hence, the way a parent is used in a cross (i.e., as female or male) will offset trait segregation. Using fast-cooking bean cultivars in conjunction with fuel-efficient cooking methods may be the best strategy to conserve fuelwood and help reduce the rate of deforestation in East and Central Africa.
S.M. Smith, J.W. Scott, J.A. Bartz, and S.A. Sargent
lycopersicum L. formerly Lycopersicon esculentum Mill) (see Peralta et al., 2006 ) that can be inoculated by water absorption through the stem scar when the fruit are immersed in the water of a packinghouse dump tank. Processed tomatoes do not typically
William R. Argo and John A. Biernbaum
Hybrid impatiens were grown in 15 cm pots containing one of six root medium. After seven weeks, plant available water holding capacity (AWHC) was measured as the difference between the drained weight of the plant and pot after a one hour saturation and the weight of the pot when the plant wilted. Water absorption potential (WAP) was calculated as the capacity of each root medium to absorb applied irrigation water up to the AWHC and was measured at two moisture levels with top watering (two leaching fractions), drip irrigation (two leaching fractions) and flood subirrigation. Top watering moist media (initial AWHC = 35%) with leaching fractions of 30+ % was me most efficient method of rewetting media and was the only irrigation method tested to obtain WAP's of 100%. In comparison, flood subirrigation was the least efficient method of rewetting media with WAP of 27% for dry media (initial AWHC = 0%), and obtained a total WAP of 55% for moist media (initial AWHC = 23%). In media comparisons, the incorporation of a wetting agent into a 70% peat/30% bark mix at planting increased the WAP compared to the same media without a wetting agent with nine of the ten irrigation treatments.
Krista C. Shellie and George L. Hosfield
Genetic and environmental interactions for bean cooking time, water absorption, and protein content were estimated with 10 dry bean (Phaseolus vulgaris L.) cultivars grown at three locations in Rwanda, Africa, during five consecutive harvests. The genotypic variance component was larger than genotype × environment variance components for the cooking time index and percent water absorption. No significant genotypic effect was observed for seed protein content. The phenotypic correlation (-0.37) between the cooking time index and percent water absorption was not strong enough to justify the use of water absorption as an indirect selection method for cooking time. The most efficient allocation of resources to evaluate the cooking time of common bean cultivars with a 25-pin bar-drop cooker was four field replications over two harvests at two locations. Water absorption was evaluated most efficiently with four field replications over two harvests at a single location.
Donna A. Marshall, James M. Spiers, and Kenneth J. Curry
of splitting. Percent split fruit was calculated. Total water absorption by fruit was calculated at all stages of development by soaking in distilled water. Weight increase of 50 berries after soaking was measured and the percent weight increase was
Marco Beyer and Moritz Knoche
Rain-induced cracking of sweet cherry (Prunus avium L.) fruit is thought to be related to water absorption through the fruit surface. Conductance for water uptake (gtot. uptake) through the fruit surface of `Sam' sweet cherry was studied gravimetrically by monitoring water penetration from a donor solution of deionized water through segments of the outer pericarp into a polyethyleneglycol (PEG) containing receiver solution. Segments consisting of cuticle plus five to eight cell layers of epidermal and hypodermal tissue were mounted in stainless steel diffusion cells. Conductance was calculated from flow rates of water across the segment and the difference in osmotic potential between donor and receiver solution. Flow rates were constant up to 12 hours and decreased thereafter. A log normal distribution of gtot. uptake was observed with a median of 0.97 × 10-7 m·s-1. Further, gtot. uptake was not affected by storage duration (up to 71 days) of fruit used as a source of segments, thickness of segments (range 0.1 to 4.8 mm), or segment area exposed in the diffusion cell. Osmolality of the receiver solution in the range from 1140 to 3400 mmol·kg-1 had no effect on gtot. uptake (1.45 ± 0.42 × 10-7 m·s-1), but gtot. uptake increased by 301% (4.37 ± 0.46 × 10-7 m·s-1) at 300 mmol·kg-1. gtot. uptake was highest in the stylar scar region of the fruit (1.44 ± 0.16 × 10-7 m·s-1) followed by cheek (1.02 ±0.21 × 10-7 m·s-1), suture (0.57 ±0.17 × 10-7 m·s-1) and pedicel cavity regions (0.22 ±0.09 × 10-7 m·s-1). Across regions, gtot. uptake was related positively to stomatal density. Extracting total cuticular wax by dipping fruit in chloroform/methanol increased gtot. uptake from 1.18 ± 0.23 × 10-7 m·s-1 to 2.58 ± 0.41 × 10-7 m·s-1, but removing epicuticular wax by cellulose acetate stripping had no effect (1.59 ± 0.28 × 10-7 m·s-1). Water flux increased with increasing temperature (range 20 to 45 °C). Conductance differed between cultivars with `Hedelfinger' sweet cherry having the highest gtot. uptake (2.81 ± 0.26 × 10-7 m·s-1), followed by `Namare' (2.68 ± 0.26 × 10-7 m·s-1), `Kordia' (0.96 ± 0.14 × 10-7 m·s-1), `Sam' (0.87 ± 0.15 × 10-7 m·s-1), and `Adriana' (0.33 ± 0.02 × 10-7 m·s-1). The diffusion cell system described herein may be useful in analyzing conductance in water uptake through the fruit surface of sweet cherry and its potential relevance for fruit cracking.
William R. Argo
Acceptable physical properties are an integral part of root-media quality. However, there is no one growing medium that works best in all situations because root-media physical properties are not constant, but rather can be affected by the grower. Understanding the root environment under production conditions requires an understanding of the dynamic nature of air : water : solid ratio in the medium. The objective of this review is to consider key aspects of root-medium physical properties, which include bulk density and particle size, container capacity, media settling, water absorption, rewettability, moisture release characteristics, and water loss due to evaporation from the root-medium surface.
Hailin Liu, Cunmeng Qian, Jian Zhou, Xiaoyan Zhang, Qiuyue Ma, and Shuxian Li
to test the water absorption capability of the seed. In Expt. I, 30 intact seeds enclosed within the endocarp were weighed on an electronic balance accurate to 0.001 g, then were immersed in 200 mL distilled water at room temperature for 168 h. At 12
. Measurement of water and calcium absorption. We constructed a measuring device for the rates of water absorption (mL·h −1 ) and calcium absorption (μmol·h −1 ) per plant following the previous study ( Sago et al., 2011a ). This system consists of a root