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- Author or Editor: J. Scott Cameron x
The criminal justice system is served by many experts who provide special assistance to law enforcement professionals during criminal investigations. One of these specialized areas. forensic botany, has traditionally been an activity of the systematic botanist who identifies plant material associated with a suspect or crime scene. From this Information, suspects can be placed at crime scenes and information such as time of death or movement of victims can be determined. Few plant scientists are involved In this emerging field which has the potential to make contributions similar to those made today by forensic anthropology.
Plant scientists with training In systematic botany, plant anatomy, plant growth and development, and statistics and probability can make significant contributions to criminal investigations. The use of plant identification and plant growth analyses In recent criminal Investigations will be described. The role of horticulture in the future of forensic science and the development of new techniques In forensic plant science will also be discussed.
Gas exchange measurements were made on healthy and rose bloom infected branches of cranberry on 31 May 1991 during the middle of the sporing period. CO2 assimilation rates of infected branches were reduced 89% on a leaf area basis and 95% on a dry weight basis compared to healthy tissue. Stomatal conductance was 12× higher in infected tissue, while mesophyll conductance was reduced by 92%. Transpiration was 4× higher in diseased tissue reducing water use efficiency by 96%.
Total chlorophyll content of diseased tissue was 81% less than that of healthy tissue but chlorophyll a/b was unchanged. Fourth derivative profiles of chlorophyll action spectra were altered in diseased tissue. Rose bloom leaves were found to lack stomata and have no discernable mesophyll layer.
Fragaria chiloensis (Linnaeus) Is a viable. low maintenance alternative to groundcovers currently available in the ornamental landscape industry. There is considerable genetic variability within this specks for leaf morphology, growth and flowering habits as well as drought tolerance. Clones collected from 11 coastal sites in CA and OR were compared for drought tolerance after two Imposed water stress\recovery cycles. Predawn water potential, gas exchange, chlorophyll (chl) content, fourth derivative spectroscopy, carbon isotope discrimination, and total biomass production were evaluated and significant clonal differences were observed.
Predawn water potentials after the first stress cycle ranged from -35.0 MPa to -6.5 MPa. Clones I05, DNT and G19 had highest predawn water potentials and gas exchange rates after both stress cycles. In the control group, I05 and DNT had higher levels of chl a, chl b, total chl and chl a\b. After the first stress cycle, clones DNT and I05 had the highest chl a\b ratio, however, after the second stress event there were no differences In any chl parameters. Varying adaptive abilities observed may suggest differential use in the landscape.
Twenty-five female clones of Fragaria chiloensis (L.) Duchesene collected from the California and Oregon coasts were surveyed for gas exchange rates under field conditions. Carbon assimilation (A) rates of native clones were 25% to 69% higher than for `Totem' (Fragaria × ananassa Duchesne) on a leaf-area basis (μmol of CO2 per sec/m2) and 7% to 77% higher when expressed on a leaf dry-weight basis (μmol of CO2 per kg dry wt/sec). Higher rates of stomatal conductance (gs) were observed in 16 of 25 F. chiloensis clones than in `Totem', with nine of 25 clones also having higher rates of transpiration (E). All clones had higher rates of residual conductance (gr) and greater water use efficiency (WUE) than the cultivated standard. The gas exchange characteristics of four strawberry cultivars (F. × ananassa) and four F. chiloensis genotypes were compared under standard greenhouse conditions. F. chiloensis genotypes had higher rates of A than cultivars when expressed on per leaf-area and dry-weight bases. Native clones also had higher rates of gs, gr, E, and WUE and greater quantum yield. Differences in chlorophyll content were observed among genotypes, but not between species.
Several anatomical and physiological parameters were measured in 32 genotypes of fragaia, including the cultivated strawberry (frapria × ananassa) and its progenitor speck F. chiloensis and F. virginiana Measurements were made using potted. runner-propagated, &month-old greenhouse-grown plants growing under long day (14/10) conditions.
Significant differences in CO2 assimilation rates (leaf area and dry weight bases). leaf chlorophyll content, leaf soluble protein content, and leaf anatomy were found between subspecies of F. virginana as well as among species. Recessed stomata and greater water use efficiency were observed in F. virginana ssp glauca as well as in F. chiloensis genotypes. In addition, it appears that leaf anatomy characteristics, as studied using light microscopy, may he useful in corroborating taxonomic decisions based upon gross morphology in Fragaria.
Abstract
In the article “The Carbohydrate-Nitrogen Relationship and Flowering/Fruiting: Kraus and Kraybill Revisted” by J. Scott Cameron and Frank G. Dennis, Jr. (HortScience 21:1099–1102, Oct. 1986), on p. 1100, under Experimental methods and designs, the authors note that the sentence reading “Kraus and Kraybill describe 4 experiments (I, III, IV, and V II)...” should read “Kraus and Kraybill describe 4 experiments (II, V, VI, and V II)...” In the article “Gene Transfer System for Potato” by Elias A. Shahin and Robert B. Simpson (HortScience 21:1199–1201, Oct. 1986), an incorrect photograph was printed as Fig. 2C. The correct photograph is printed below.
Abstract
Micropropagated mother plants of strawberry (Fragaria × ananassa Duchesne) often produce more flowers and runners than their runner-propagated counterparts (4, 5), but it is not clear how long this effect lasts. Swartz et al. (5) reported that the increase in runnering of tissue culture plants did not continue after the first flush of runner production in the field, and Marcotrigiano et al. (4) showed that, within the planting year, micropropagation increased runner production in mother plants and their primary runner plants, but not in attached secondary and tertiary runner plants. However, these studies examined runner plants still attached to plants directly out of culture, rather than detached, cold-hardened plants as they are delivered to the grower. In a study where detached runner plants of unknown age were compared, planting stock from micropropagated plants of 4 of 6 cultivars had significantly higher matted row densities (
Leaf water potential (LWP). relative water content (RWC), gas exchange rates and 4th-derivative spectra were measured in water-stressed and normally Irrigated plank of Totem' strawberry (Fragaria × ananassa) grown in a growth chamber. CO2 assimilation rate (A) dropped sharply when LWP decreased from -0.5 to -1.2 MPa and almost ceased as LWP fell below -1.5 MPa. There was a significant but more gradual decline of A as RWC decreased form 90% to 55%. An exponential relationship with A was observed across a wide range of LWP and RWC (Rz= 0.64, 0.86, respectively). LWP was more closely related with transpiration and leaf and stomatal conductances than with A and water use efficiency. RWC was highly correlated with all gas exchange parameters.
Under moderate water stress, younger leaves maintain higher RWC and A than older leaves. There was no relationship between LWP and leaf age.
RWC and A were both negatively correlated with peak amplitudes of Ca 684 and Ca 697 and positively correlated with Ca 693 in their 4th-derivative spectra of chlorophyll. LWP had a negative correlation with Cb 640.
In 1998, yield of the split (ST) vs. conventional trellis was again compared in `Meeker' red raspberry with work at Vancouver focusing on advanced trellis development and technology transfer. Field testing was expanded from two to five sites in northern (Lynden) and southwestern (Woodland, Ridgefield, WSUV REU) Washington, with a total of eight trials. These tested a variety of widths (28–51 cm), crossarm styles, and machine harvesters in fields with varied cultural practices. Four trials were machine-picked, and, in Vancouver, harvest efficiency was studied. For widths >43 cm, yields were 10% to 13% greater for ST in four trials, while widths less than 43 cm showed no increase. As in previous years, estimated yield potential was 20% to 59% higher for ST in three of four trials. Differences between actual/estimated yields were due to several factors, including damage to laterals, harvest inefficiency, and poor early fruit release. Yield potential was greater (28%) for ST in a second-year trial, suggesting sustainability. In various trials, numerous data were collected including canopy and primocane measurements, aboveground biomass, light interception and leaf: area, gas exchange, chlorophyll content, fourth derivative spectra, fluorescence, N content, and tissue for anatomical analysis. Results were similar to last year. Increased light within ST causes earlier and larger canopy growth and fruit development. There was a large increase in leaf number, leaf area and berry number. Increases in yield were again associated with higher number of lateral/cane. There was no difference in leaf physiological measurements/leaf area between treatments.
Leaf fluorescence characteristics, chlorophyll (Chl) content and 4th-derivative spectra were measured six times before, during, and after water stress development in F. chiloensis and F. ×ananassa grown in growth chambers. The younger strawberry leaves under water stress maintained higher Chl a, Chl b, and total Chl contents than those under nonstressed conditions, while the older ones lost Chl quickly under water stress and then died. In comparison to F. ×ananassa, F. chiloensis had significantly higher Chl a, Chl b, and total Chl contents and peak amplitudes of Cb 630 and Ca 693 in 4th-derivative spectra under stressed and nonstressed conditions. The differences in peak amplitude of Ca 693 between the two species increased under water stress. Fq was the most sensitive fluorescence characteristic to water stress and was reduced significantly under stress. Fm and Fv decreased significantly under more severe water stress. A reduction in Fv suggests that severe water stress might cause thylakoid damage and photoinhibition in the leaves, which resulted in a very depressed CO2 assimilation level. F. chiloensis had significantly higher Ft and Fq before and under water stress development (but not after stress recovery) than F. ×ananassa.