Cotyledon Width Research Articles

Placental traits and maternal intrinsic factors affected by parity and breed in goats

The relationship between placental traits and maternal intrinsic factors of Saanen, German Fawn and Damascus goats was investigated. Data was collected from 93 goats. The results of the study demonstrated that there were positive correlations between placental weight (PW) and cotyledon number (CN) ( r = 0.498, P < 0.01), cotyledon weight (CW) ( r = 0.880, P < 0.01), cotyledon density (CD) ( r = 0.538, P < 0.01), cotyledon width (CWI) ( r = 0.500, P < 0.01) cotyledon length (CL) ( r = 0.414, P < 0.01) and cotyledon density (CD) ( r = 0.278, P < 0.05). CN was negatively correlated with placental efficiency (PE) ( r = −0.421, P < 0.01) and CD ( r = −0.325, P < 0.05). While expulsion of placenta, right teat length and cotyledon length were affected by parity of doe ( P < 0.05) birth weight (BW), CN, right teat diameter (RTD), left teat diameter (LTD), CD, and CL were affected by breed ( P < 0.01). Breed × parity was found significant both for expulsion time of placenta and left teat length (LTL) ( P < 0.05). Damascus goats had a significantly longer duration of licking and grooming events than others. Saanen was more likely to require birth assistance compared to the German Fawn.

Variation in agro-morphological characteristics of cacao, Theobroma cacao L., in farmers' fields in Nigeria

Knowledge of available variability in a crop species provides a guide for the utilization and conservation of useful variation. Seventeen agro-morphological traits were studied in 184 accessions of cacao, Theobroma cacao L. collected from farmers' fields (138) and field genebank collections (46). Descriptive statistics—univariate analysis of variance (ANOVA)—were used to determine variation among accessions. Multivariate analysis with principal component analysis (PCA) was done and a cluster dendrogram was generated based on the unweighted pair group mean with arithmetic average (UPGMA). The first three principal component axes accounted for 43.6% of total variation observed among accessions studied. Quantitative bean traits—dry bean weight, nib weight, fresh weight, cotyledon length and cotyledon width—and qualitative fruit traits—basal constriction, apex form, ridge colour, fruit shape, flush colour and cotyledon shape—were the most important traits accounting for the variability observed. Six groups of accessions were obtained from cluster analysis. Fruit and bean traits of Upper Amazon Forasteros observed in farmers' accessions provided evidence of a shift from previously grown local ‘West African Amelonado’ from the Lower Amazon Forastero population. In conclusion, this study revealed some accessions with useful trait combinations in farmers' plantations and indicated a need to conserve the local ‘Amelonado’ landrace variety to avoid extinction and to preserve the unique flavour of ‘West African Amelonado’ in cocoa breeding programmes.

Morphological characterization of Hungarian and Turkish watermelon (Citrullus lanatus (Thunb.) Matsum. et Nakai) genetic resources

Thirty-nine Hungarian accessions either collected from different regions of Hungary or obtained from gene banks and 11 Turkish accessions representing particular regions of Turkey were evaluated and compared for morphological characteristics. Qualitative characters were obtained according to the modified UPOV descriptor list for 58 characters. Sixteen quantitative characters (hypocotyl length, cotyledon width and length, length of main stem, number of nodes, length and width of leaf, length of petiole, length and width of the ovary, fruit weight, size of pistil scar, diameter and length of fruit, thickness of outer layer of pericarp, total soluble solids) were also measured. Results of both qualitative and quantitative measurements indicated that Hungarian and Turkish germplasm resources present a wide range of diversity for morphological traits. Accessions of the two countries show many similarities, therefore cannot be separated clearly. Considering the historical background, the two countries might have varieties with similar phenotypes and genetically common backgrounds.

박과채소용 단근합접 접목시스템 개발(1) -작업공정 분석과 시스템 설정 -

This study was conducted to develop a root-removed splice grafting system for cucurbitaceous vegetables, mainly watermelon and cucumber seedlings, for the seedlings factories where currently most of seedlings grafting works are carried out by manual works. The major results of the study are as follows. The dimensions of rootstocks and scions, except cotyledon width, of root- removed splice grafting of watermelon and cucumber were shown to be varied within the 2.5-fold range. The growth status of seedlings were not consistent in terms of cotyledon sprouting direction and angle which were considered as one of the important factors for in root-removed splice grafting. The grafting work of root-removed splice for grafted watermelon and cucumber could be divided by four sub-operations: seedling supplying, cutting, clipping and potting, while a part or all root of the rootstock was removed in the seedlings supplying operation. The cutting angles of the rootstock and scion were and , respectively, while the stem length of the scion varied from 6 mm to 12 mm. The splices of rootstock and scion were heaped up in parallel and then fixed by a clip. It indicated that the ideal grafting system, adopting conventional grafting processes of seedlings specifications as well as conventionally manual root-removed splice grafting method, performed very well for seedlings gripping and transporting, supplying clip, clipping and discharging grafted seedlings while workers supplied seedlings to the semi-automatical system.

Calcium and humic acid affect seed germination, growth, and nutrient content of tomato (Lycopersicon esculentum L.) seedlings under saline soil conditions

The effects of calcium and humic acid on seed germination, growth and macro- and micro-nutrient contents of tomato (Lycopersicon esculentum L.) seedlings in saline soil conditions were evaluated. Different levels of humic acid (0, 500, 1000 and 2000 mg kg−1) and calcium (0, 100, 200 and 400 mg kg−1) were applied to growth media treated with 50 mg NaCl kg−1 before sowing seeds. Seed germination, hypocotyl length, cotyledon width and length, root size, shoot length, leaf number, shoot and root fresh weights, and shoot and root dry weights of the plant seedlings were determined. Macro- and micro-nutrient (N, P, K, Ca, Mg, S, Cu, Fe, Mn and Zn) contents of shoot and root of seedlings were also measured. Humic acid applied to the plant growth medium at 1000 mg kg−1 concentration increased seedling growth and nutrient contents of plants. Humic acid not only increased macro-nutrient contents, but also enhanced micro-nutrient contents of plant organs. However, high levels of humic acid arrested plant growth or decreased nutrient contents. Levels of 100 and 200 mg kg−1 Ca2+ application significantly increased N, Ca and S contents of shoot, and N and K contents of root.

Physiological Characterization of the Response of Excised Etiolated Cucumber Cotyledons to Benzyladenine: Expansion Begins at 30 Minutes

Summary Benzyladenine (BA) and other cytokinins are known to induce a three-part physiological response in excised, dark-grown cucumber ( Cucumis sativus L.) cotyledons consisting of a) increased size and fresh weight, b) more prominent veins, and c) increased yellowing due to carotenoid biosynthesis. Based upon an analysis of long-term kinetics, the three elements of this response occurred roughly in parallel rather than sequentially. KCl (20 mmol · L −1 optimum) promoted all three elements, especially when supplied with BA, but RbCl had no effect. As measured by increase in cotyledon width, BA-induced expansion was extrapolated to begin at approximately 30 min with linear kinetics for at least the first 2 h. KCl promoted the growth rate (1.7-fold at 2 h) but failed to decrease the lag time. This lag time, far shorter than any previous determination using cytokinin-treated cotyledons, is in the range reported for auxin- and gibberellin-responsive elongating systems. Fusicoccin promoted growth even more quickly and with greater initial rate than BA (2.9-fold at 2 h). As found in many plant tissues responsive to auxin and gibberellin, but in contrast to cytokinin-treated radish cotyledons, cell wall synthesis in cucumber cotyledons was promoted by BA (1.5-fold at 48 h). 2,6-dichlorobenwnitrile, a potent inhibitor of cellulose biosynthesis, had no effect on overall BA-induced cotyledon growth as measured at 24 h but completely abolished vein enlargement. As discussed, these results indicate that auxin-, gibberellin-, and cytokinin-induced cell expansion have apparent physiological similarities in terms of early kinetics and cell wall synthesis.

Latitudinal variation in plant size and relative growth rate in Arabidopsis thaliana

Latitude is an important determinant of local environmental conditions that affect plant growth. Forty ecotypes of Arabidopsis thaliana were selected from a wide range of latitudes (from 16°N to 63°N) to investigate genetic variation in plant size and relative growth rate (RGR) along a latitudinal gradient. Plants were grown in a greenhouse for 31 days, during which period three consecutive harvests were performed. Plants from high latitudes tended to have smaller plant size in terms of seed size, cotyledon width, rosette size, number of rosette leaves, size (leaf area) of the largest leaves, total leaf area, and total dry weight per plant than those from low latitudes. The mean (±SE) RGR across ecotypes was 0.229 (±0.0013) day-1. There was, however, significant ecotypic variation, with RGR being negatively correlated with latitude. The two main components of RGR, leaf area ratio (LAR) and unit leaf rate (ULR), were also correlated with latitude: LAR increased with increasing latitude while ULR decreased with increasing latitude. It was also found that RGR tended to be negatively correlated with LAR, specific leaf area (SLA) and specific root length (SRL) but to be positively correlated with mean area per leaf (MAL) and ULR. The variation in RGR among ecotypes was relatively small compared with that in the other traits. RGR may be a conservative trait, whose variation is constrained by the trade-off between its physiological (i.e. ULR) and morphological (i.e. LAR) components.

Influence of Seedling Pretreatment and Explant Type on Watermelon Shoot Organogenesis

Several methods have been published on shoot regeneration from watermelon cotyledon explants. The major differences in regeneration protocols include the light environment in which seeds are germinated and the cotyledon region used. The purpose of these experiments was to compare the two main protocols for plant regeneration and develop one general procedure. To fulfill this objective, seeds were germinated in vitro in darkness or 16-hr light photoperiod for 7 days. Cotyledon explants from four watermelon cultivars (`Crimson Sweet', `Minilee', `Sweet Gem', and `Yellow Doll') were prepared from both dark- and light-grown seedlings. Apical and basal halves were obtained by making a cut across the cotyledon width. Apical and basal quarters were made, for comparison, by cutting apical and basal halves longitudinally. All explants were incubated on shoot regeneration medium for 6 weeks followed by a 3-week cycle on shoot elonga-tion medium. The percentage of cotyledons with shoots was 1.7-fold greater for cotyledons derived from seedings incubated in darkness than those germinated in light. Shoot formation was about 10-fold greater for explants from cotyledon basal halves and quarters than apical halves and quarters. According to these results, the best watermelon regeneration protocol should consists of basal explants from in vitro-germinated seedlings incubated in the dark for 7 days.

Developmental instability in Brassica campestris (Cruciferae): fluctuating asymmetry of foliar and floral traits

AbstractThe degree of fluctuating asymmetry of bilateral traits provides a measure of developmental instability, which can be influenced by genetic as well as environmental stress. We studied genetic variation between and within two populations of the mustard Brassica campestris for asymmetry of foliar (cotyledon width) and floral (petal length and width) traits as well as for phenological (germination and flowering) and performance (biomass and flowering) traits. The two populations differed in mean expression of most traits, including asymmetry. However, within‐population estimates of genetic variability tended to be lower for asymmetry than other traits. Asymmetry was greater in the population that had lower biomass accumulation and flower production, which supports the idea that population‐level asymmetry may be indicative of population‐level performance. However, within each population, evidence that performance was negatively correlated with asymmetry was equivocal. Within populations there was little or no concordance among estimates of asymmetry based on different structures, i.e., plants that had highly asymmetrical cotyledons did not tend to have highly asymmetrical petals. The lack of a general buffering capacity at the individual level may be explained by developmental processes (e.g., action of different genes or morphogens) as well as evolutionary processes (e.g., selection on asymmetry of different traits).

Seed size and emergence time within a stand of wild radish (Raphanus raphanistrum L.): the establishment of a fitness hierarchy.

To determine the role of seed size in creating adult plants of different reproductive success, individual seedlings were marked and periodically censused in a natural stand of wild radish (Raphanus raphanistrum L.) in Hamden, Connecticut. Maximum cotyledon witdth is a useful field estimator of seed weight in this species, although dramatic variation in the availability of water can modify this relationship. Using maximum cotyledon width as a linear estimate of seed weight showed that an increase in seed weight gives rise to a disproportionately large increase in an individual's total reproductive output. Analysis of covariance demonstrated that reproductive output is influenced more heavily by seed weight (maximum cotyledon width) than by emergence time. Genetic variation for seed size has been maintained in this population, suggesting that selection favoring large seeds during the seedling stage may be counteracted by selection for large numbers of seeds.