Fresh Stigma Research Articles

Evaluating the Effects of Bacillus subtilis Treatment and Planting Depth on Saffron (Crocus sativus L.) Production in a Green Roof System

Given the current urbanization context and rising interest in green roof systems, growing a high-value crop such as saffron crocus in green roof medium could be an opportunity to use the benefits of both the crop and the green roof system; the drainage, aeration, and sand-like texture of green roof media make it suited for saffron production, and the saffron market price could make green roof production commercially viable. Various factors, including plant diseases and planting depth, could affect saffron production. Therefore, this research was conducted to evaluate the effects of planting depth and biofungicide treatments using Bacillus subtilis on saffron production in a green roof system. A completely randomized factorial block design was used with planting depth (10 cm and 15 cm) and B. subtilis strain QST 713 biofungicide treatments (an untreated control, 15.6 × 109 cfu/L, and 31.2 × 109 cfu/L) as independent variables. In 2019, fresh flower yield, fresh stigma yield, and dry stigma yield were calculated during harvesting, and additional data on flower number, tepal length and width, stigma length, and harvest time were collected in 2020. All variables were analyzed using analysis of variance (ANOVA) with planting depth and biofungicide treatments as fixed effects using R. Fresh stigma yield and dry stigma yield were higher in the 10-cm planting depth in 2019. Results were opposite in 2020: flower number, fresh flower yield, fresh stigma yield, dry stigma yield, and harvest time were higher in the 15-cm planting depth than the 10-cm planting depth. B. subtilis treatments did not affect any studied variable in 2020, but in 2019, the higher level of fungicide treatment resulted in lower fresh flower yield and dry stigma yield. There was no effect of biofungicide treatment and planting depth on tepal length, tepal width, and stigma length in both years. This study showed that growing saffron crocus on green roofs is feasible and even resulted in higher yield than field production in many saffron-producing regions and countries. In addition, results indicated that shallow planting might be suitable for annual production, whereas deeper planting could be ideal for perennial production based on the objective. Our findings demonstrated the feasibility of saffron production in the green roof system and suggest further research to develop best management practices.

Agro-Climatic Suitability Evaluation for Saffron Production in Areas of Western Himalaya.

Saffron (Crocus sativus L.) is an expensive spice crop cultivated successfully in Iran, Afghanistan, India, Greece, Morocco, Spain, and Italy. The present study was conducted during the periods 2018–2019 and 2019–2020 to evaluate the morphological, yield and quality parameters of saffron in six different regions of non-traditional areas of the western Himalayas. The two experimental factors were “year” and “location.” The experiment was conducted using a factorial randomized block design with three replications. Yield attributes, viz., number of flowers, fresh flower yield, fresh stigma yield and dry stigma yield were significantly higher in location L3 compared to other geographical locations. Dry stigma yield in location L3 was higher by 50.0, 41.2, 33.3, 14.3, and 9.1% compared to locations L6, L5, L1, L4, and L2, respectively. These were characterized by the appropriate climatic conditions, viz., high altitude, sandy-loam texture of the soil, optimum temperature, lesser relative humidity and total rainfall, demonstrating that it is possible to cultivate this spice even in non-traditional areas of the western Himalaya. Positive correlations were established for stigma yield with increased altitude and lesser rainfall. Secondary metabolites viz., crocin and picrocrocin increased significantly with the increase in altitude; however, a reverse trend was recorded for safranal content. Total phenolics and flavonoids were significantly higher in the geographical location of Kinnaur, H.P. (L1) and Bharmour, H.P. (L4). In conclusion, the assessment of different geographical locations and soil types is particularly necessary to encourage saffron production and its qualitative traits. Based on current findings, saffron can be grown successfully in some non-traditional locations of the western Himalayan regions.

Pulsed electric fields (PEF) as hot air drying pre-treatment: Effect on quality and functional properties of saffron (Crocus sativus L.)

This study aimed to investigate the use of pulsed electric fields (PEF) (2 kV/ cm; 1.5 KJ kg−1) as pre-treatment to the hot air drying process for the improvement of quality and functional properties of saffron. Analysis of flavouring, aroma and colouring strength (E1%λmax), crocins pattern (UHPLC-MS/MS), total polyphenol content (TPC) and antioxidant activity (AOA) were performed after processing and during aging at room temperature. Microstructure of fresh and processed stigmas was also assessed.PEF decreased (≈ −41%) the flavour, aroma and colouring strength of stigmas and negatively influenced the safranal production during drying; nevertheless, stigmas pre-treated by PEF (PD) after 3 months of aging showed quality properties similar to those of not pre-treated sample (D). Analysis of crocins by UHPLC-MS/MS highlighted a negative effect of PEF on trans-cis crocins ratio and showed poor correlation with colour strength. PEF did not influence the TPC of fresh stigmas but after drying and aging PD showed the highest value among the samples. PEF negatively influenced (−24%) the AOA of fresh stigma while favored its increase during drying. Loss of AOA during aging (up to 86%) was processing independent. Microstructure analysis showed that PEF treatment strongly impaired the stigmas' cells, thus enhancing the extractability of intracellular compounds.

Effect of changes in planting depths of saffron (Crocus sativus L.) corms and determining their agronomic characteristics under warm and temperate (Csa) climatic conditions of Turkish province of Hatay

The study was carried out under warm and temperate (Csa - Kopen Gegger classification) ecological conditions of Turkish province of Hatay during 2010-2011 using saffron (Crocus sativus L.) corms of three different circumference by planting them at 5 and 15 cm depths. Saffron corms were divided into three categories based on circumference; large: more than 8 cm, medium: 6-8 cm and small 4-6 cm. The number of corms, number of flowers, fresh stigma yield, number of leaves, number of harvested corms and their weight were evaluated after harvest. The results showed that the number of flowers were positively affected by their circumference at both planting depths. Surface planted corms showed proportionally increased regeneration of new cormlets. The stigma yield was positively affected using different corms circumferences in the second year, but had no significant effect at different depths. Increased weight of harvested cormlets was noted on corms planted at 15 cm depth during the 2nd year. Second year planting at 15 cm depth showed markedly increased corm circumference, improved number of flowers, stigmas yield compared to the these parameters noted after first year planting with planting.

Phenotypic and genotypic relationships between traits in saffron (Crocus sativus L.) as revealed by path analysis

To study and assess the phenotypic and genotypic variations between different saffron ecotypes and the phenotypic/genotypic relationships between yield and yield components of saffron flower a split plot experiment in randomized complete block design with three replications was conducted at the agricultural research station of Urmia University, Urmia, Iran during 2011-13 cropping years. 15 traits of yield and yield components of saffron flower were measured such as: Fresh Stigma Weight, Dry Stigma Weight and Stigma Length. The results showed that genetic variances were much higher than phenotypic variances for more traits. Fresh and dry leaf weight (94 and 95% respectively) and dry stigma yield (94%) had the highest heritability between traits. It became also very clear that these traits had the highest genetic diversity. Results of the correlation coefficients showed that the phenotypic correlations were higher than the genotypic correlations for almost of all traits. Traits daughter corm number (0.98), flower number (0.97), dry and fresh daughter corm weight (0.96 and 0.95, respectively) and dry stigma weight had the highest genotypic correlation with dry stigma yield. Phenotypic and genotypic path analysis determined that fresh and dry stigma weight, flower number, leaf width and dry flower weight had the highest positive direct effects on dry stigma yield. In general, with the purpose of the study and assessments to genotypic correlation coefficients, genetic parameters and genotypic direct and indirect effects, we can conclude that traits flower number, leaf number, weight and number of daughter corm were the most effective traits and had the highest positive impacts on the saffron yield. Therefore, with the phenotypic selection of saffron ecotypes in respect of these traits the saffron yield can be increased.

Saffron (Crocus sativus L.): The effect of mother corm size on progeny multiplication, flower and stigma production

The three year study of saffron (Crocus sativus L.) production from 27 mother corm weight grades, investigated mother corm progeny multiplication, corm weight, flower number and fresh stigma yield. Annual production results were pooled into 9 mother corm weight classes (0.5, 1–2, 3–5, 6–10, 11–15, 16–20, 22–30, 34–36, 38–53g), and 5 progeny corm weight grades (<5, 5–10, 10–15, 15–20, >20g). Yearly production equations were fitted for total progeny corm number and weight from the 27 mother corm classes. In year 1, the fitted asymptotic curve showed mother corm weight above 16g had little effect on progeny corm number, but in year 2, a linear relationship showed the production of progeny corms was not constrained by the original mother corm weight, while in year 3, progeny corm number was constrained to an asymptote of 69 corms per original mother corm. We measured large changes in the distribution of progeny corm size over the three generations. For the three respective harvest years mother corms >33g produced 22, 47 and 22% of their progeny corms >10g and of these 6, 30 and 0.4% were >20g. For the three respective harvest years, mother corm weight classes >33g, produced 7, 30 and 69 progeny corms with a weight of 60, 406 and 427g, while the 11–15g mother corm class produced 4.8, 10.3, and 45 progeny corms with a weight of 35, 144 and 356g. Cumulative flowering followed a typical sigmoid curve with the main flowering period for the heavier grades of mother corms finishing after 45 days in the first year and 25–30 days in the two subsequent years. Smaller corms flowered 5–7 days later than the largest corms, while mother corms lighter than 2g produced very few flowers. The mother corm weight classes >33g produced 4, 16 and 48 flowers and 115, 627 and 1905mg of fresh stigma per original corm over the three generations. In contrast the 11–15g mother corm weight class produced 1, 4 and 20 flowers and 29, 171 and 906mg fresh stigma per original corm. We conclude the flower and fresh stigma production is highest in a 3 year management cycle, but if large progeny corms are desired a 2 year management cycle would produce more large progeny corms.

Pollination biology of Gelsemium sempervirensL. (Ait.) (Gelsemiaceae): do male and female Habropoda laboriosa F. (Hymenoptera, Apidae) differ in pollination efficiency?

SummaryIn the outer coastal plain of Georgia, USA, Gelsemium sempervirens (Gelsemiaceae) is heavily visited (69–100% of all flower visits) by male and female blueberry bees, Habropoda laboriosa (Hymenoptera-Apidae). Fruit set is, however, consistently low (8–36% range). The pollination efficiency of male and female blueberry bees was studied using: 1. comparison of pollen loads on foraging male and female bees; 2. calculation of pollen loads on fresh stigmas of flowers exposed to a single visit by a female bee; and 3. an experimental test of fruit and seed set following exposure to one to eight visits by both male and female bees. Females had larger pollen loads in four of five body regions, but male bees consistently carried pollen in quantities sufficient for fertilization. A single visit from a female bee resulted in mixed pollen deposition of 76 pollen grains, 20 of which were from Gelsemium and 56 from Vaccinium. There was no significant relationship of either fruit or seed set with number of visits from either males or females. Whilst both male and female bees are effective as pollen delivery agents of G. sempervirens, much of the pollen they deliver may be from the same floral morph, leading to rejection in this self-incompatible distylous species. Low fruit set may also be related to other factors such as resource limitation and/or herbivory.

POLLEN LONGEVITY AND STIGMA PRE‐EMPTION IN CLARKIA

The ability of pollen to effect seed set decreases with age when stored at room temperature or on the plant, but not when stored at 5 C. Seed set declines rapidly with pollen stored 10 days or more at room temperature. Seed set declines rapidly with pollen stored 4 days or more on the plant. The degree of pollen germination on the stigma and the number of pollen tubes in the style correlate positively with seed set. Pollen germination on the stigma and pollen tube growth in the style are strongly correlated with seed set for pollen stored at room temperature, but not, or only weakly, correlated for pollen stored at 5 C. In the latter case, seed sets are lower than expected, indicating a possible viability reduction associated with a post‐pollination function. Inviable pollen grains temporarily interfere with normal pollen germination on the stigma. Essentially no seeds are produced when in viable pollen, immediately followed by viable pollen, is placed on a fresh stigma. However 27 to 65 seeds are produced when in viable pollen, followed in 1 to 6 days by viable pollen, is placed on fresh stigmas. New stigma surface is exposed at the center as expanding stigma surfaces carry the interfering inviable pollen toward the edge of the stigma.

Self-incompatibility and the pollen-stigma interaction inTradescantia ohiensis rafin

Self-incompatibility (SI) is reported for an accession ofTradescantia ohiensis. Pollen tube inhibition is stigmatic. The stigma is wet and papillate, the papillr surface bearing conspicuous blebs particularly in the mid- and basal regions of the cell. A proteinaceous pellicle is present on the surface of the papillar cuticle. The penetration of the stains calcofluor white and alcian blue into the cell wall of fresh stigma papillae strongly indicates that the permeability of the papillae is greatest at the mid-region of the cell and not at the tip. When single pollen grains are attached to the tip of a papilla there is either no response at all or the pollen adheres to the papilla. When attached in the mid-region pollen adheres, and often germinates. It is concluded that the sites of pollen receptivity are the mid- and basal regions of the papular cell.

Structure and Histochemistry of the Stigma and Style of Some Australian Species of Acacia

The structure and histochemistry of the stigma and style of Acacia conferta, A , dealbata, A . iteaphylla, A . mearnsii, A. retinodes and A. subulata were investigated in relation to the pathway of pollination. The stigma is non-papillate and forms a cup-shaped depression at the tip of the style that glistens with exudate at anthesis. This exudate is heterogeneous in microscopic appearance and stained positively for proteins, carbohydrates and lipids. No cuticle is detectable over the stigma surface and living stigma cells showed a high permeability to staining by both the periodic acid-Schiff's reaction and ruthenium red. Esterase activity, detected cytochemically in fresh stigmas, is present in the surface exudate and in the walls of the transmitting cells in the upper style. The style has a central transmitting tissue, consisting of longitudinally elongated rows of cells loosely packed in a mucilaginous extracellular matrix. The cytoplasm of the transmitting cells stained intensely for proteins.

Pollen wall proteins: pollen-stigma interactions in ragweed and Cosmos (Compositae).

ABSTRACT The release of wall-held materials from the pollen of ragweed (Ambrosia tenuifolia) and Cosmos bipimuxtus on to the stigma surface has been followed. When fresh stigmas were viewed by scanning electron microscopy, a fluid material was observed coating pollen grains, pollen tubes and adjacent stigmatic papillae. This fluid contained pollen-wall antigens, including the allergen Antigen E, detected by immunofluorescence, and proteins, lipids and carbohydrates detected by cytochemical methods. In Cosmos, the fate of the antigens was much the same after both compatible and incompatible matings. In incompatible matings, pollen tubes were blocked with a polysaccharide considered to be callose. Callose particles appeared on neighbouring stigmatic papillae, and adjacent stigmatic hairs accumulated callose internally. This reaction may be an important one for the incompatibility response.

Studies on the Pollen of Buckwheat : On the relation of its germination to temperature

Effects of temperature upon the germination of the pollen of autumn buckwheat, a common race of it grown in Iwate Prefecture, were investigated. Fresh stigmas were pollinated artificially, and after 5, 10, 30, 60 and 120 minutes, they were fixed and stained in lactic blue. Pollen grains which had germinated and developed long pollen-tubes, the contents, however remaining in the grains were graded as A; pollens, the whole contents of which had passed into the pollen tubes leaving vacant grain bodies, were graded as C; ant those which reached half-way between A and C were graded as B. Germinating pollen grains of A and B grades appeared when the stigmas were kept at 15 to 42°C., but at lower temperatures, C-grade pollens increased in number as time went by, amounting to 65.1 % of the total number. Under the temperatures higher than 42°C, C-grade germination was not observed. In general, at lower tempertures the growth of pollen-tube was slow but continuous, while at higher temperatures it was rapid at the beginning, and stopped soon afterwards leaving germination incomplete. In buckwheat plants, pollen germination was observed to take place at 18 to 30°C., its optimum being about 20°C.

CYTOLOGICAL DIFFERENTIATION IN GAILLARDIA PULCHELLA

THE BLANKET FLOWER, a widespread composite of the southern United States, is morphologically and cytologically variable. No detailed studies of this species have been made, other than the taxonomic treatments by Rydberg (1915) and Biddulph (1944). Gaillardia pulchella has had a long and confused taxonomic history. It has been split into several distinct species by some workers (Rydberg, 1915; Nelson, 1926) and confused with the related Gaillardia aristata by others. METHODS.Eighteen collections of seed of Gaillardia pulchella (table 1) from different parts of the species range were grown in a standard habitat at the Indiana University experimental garden. Chromosome counts of these races were determined from microsporocyte and root-tip preparations. Morphological characters of these wild races and their artificially produced hybrids are given in fig. 1 and 2. Reciprocal hybrids between races were produced by bagging heads before the flowers opened, then transferring pollen to the fresh stigmas daily until all flowers had been pollinated. In the following discussion of hybrids, the formulae refer to both reciprocals. Mature embryos were cultured in order to facilitate germination. Embryos were limited in number, and the abnormal germination of some decreased their chances of survival under greenhouse conditions. No morphological differences were found in reciprocals, and the frequency of crossing in either direction was the same. In culturing embryos, Tottingham's modification of Knop's solution (Miller, 1938) was used in half the normal concentrotion with 1 per cent agar added. Achenes were sterilized in sodium hypoclorite (commercial Chlorox 1 part: distilled water 7 parts) for 1 hr., dissected, and embryos were planted vertically in 2.5 cc. of mineral agar in shell vials. Cotyledons began growth in two or three days, and seedlings were transplanted to 3-in. pots approximately four weeks later. When large enough, hybrids were transplanted to the garden. Hybrids which reached maturity grew much more vigorously and bloomed more profusely than either parent. They were morphologically intermediate in most respects, and 9 selected hybrids are evaluated in fig. 2. No character found in one parent clearly dominated the contrasting character in -the other parent. All hybrids were as tall or taller than