Laboratory Exercise on the Segregation of Flower Color and Related Genes Using Salpiglossis sinuata

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 555b-555
Author(s):  
Chiwon W. Lee

Velvet flower (Salpiglossis sinuata, Solanaceae) can be used as an excellent demonstration plant for horticultural crop breeding classes. Salpiglossis produces large trumpet-like flowers exhibiting an assortment of corolla color and pigmentation pattern. The pistil is large (3 to 4 cm long) with a sticky stigmatal tip and anthers can be easily emasculated prior to anthesis. The large pollen grains are shed in tetrads, which can be separated and individually placed on the stigma. It takes 8 to 9 weeks from seeding to blooming, with a prolific flowering cycle repeated in flushes. Numerous seeds (about 750/capsule) are obtained in 3 weeks after self- or cross-pollination. The influences of three genes that control flower color and pigmentation pattern can be conveniently demonstrated with their dominant and recessive alleles. The R gene controls flower color with red (RR or Rr) being dominant over yellow (rr) flower color. The D gene controls the density of pigmentation with solid (DD or Dd) color being dominant over dilute (dd) color. Corolla color striping is controlled by the St gene with striped (stst) being recessive to non-striped (StSt or Stst) pattern. For example, by using diploid lines of genotypes RRDD (red, solid), RRdd (red, dilute), or rrdd (yellow, dilute) and their crosses, students can easily learn a dominant phenotypic expression in the F1 hybrid and the digenic 9:3:3:1 segregation ratio in the F2 progeny. Another gene (C) that controls flower opening can also be used to show its influence on cleistogamous (closed, self-pollinated, CC or Cc) versus normal chasmogamous (open-pollinated, cc) corolla development. In addition, the induction and use of polyploid (4X, 3X) plants in plant breeding can be effectively demonstrated using this species.

1999 ◽  
Vol 9 (4) ◽  
pp. 589-593
Author(s):  
Chiwon W. Lee

Velvet flower (Salpiglossis sinuata, Solanaceae) can be used as an excellent demonstration plant for horticultural crop breeding classes. Salpiglossis produces large trumpetlike flowers exhibiting an assortment of corolla colors and pigmentation patterns. The pistil is large (3 to 4 cm or 1.2 to 1.6 inches long) with a sticky stigmatal tip and flowers can be easily emasculated prior to anthesis. The large pollen grains are shed in tetrads which can be separated and placed on the stigmatal surface. It takes eight to nine weeks from seeding to blooming, with a prolific flowering cycle that comes in flushes. Numerous seeds (about 750 per capsule) are obtained in three weeks after self- or cross-pollination. The influences of three genes that control flower color and pigmentation pattern can be conveniently demonstrated with their dominant and recessive alleles. The R gene controls flower color with red (RR or Rr) being dominant over yellow (rr). The D gene controls the density of pigmentation with solid (DD or Dd) color being dominant over dilute (dd) color. Corolla color striping is controlled by the St gene with striped (stst) being recessive to nonstriped (StSt or Stst) pattern. By using diploid lines of genotypes RRDD (red, solid), RRdd (red, dilute), or rrdd (yellow, dilute) and their crosses, students can easily observe a dominant phenotypic expression in the F1 hybrid and the digenic 9:3:3:1 segregation ratio in the F2 progeny. Another gene (C) that controls flower opening can also be used to show its influence on cleistogamous (closed, selfpollinated, CC or Cc) versus normal chasmogamous (open-pollinated, cc) corolla development. In addition, the induction and use of polyploid (4x) plants in plant breeding can also be demonstrated using this species.


2007 ◽  
Author(s):  
Nurit Firon ◽  
Prem Chourey ◽  
Etan Pressman ◽  
Allen Hartwell ◽  
Kenneth J. Boote

Exposure to higher than optimal temperatures - heat-stress (HS) - is becoming increasingly common to all crop plants worldwide. Heat stress coinciding with microgametogenesis, especially during the post-meiotic phase that is marked by starch biosynthesis, is often associated with starch-deficient pollen and male sterility and ultimately, greatly reduced crop yields. The molecular basis for the high sensitivity of developing pollen grains, on one hand, and factors involved in pollen heat-tolerance, on the other, is poorly understood. The long-term goal of this project is to provide a better understanding of the genes that control pollen quality under heat-stress conditions. The specific objectives of this project were: (1) Determination of the threshold heat stress temperature(s) that affects tomato and sorghum pollen quality whether: a) Chronic mild heat stress conditions (CMHS), or b) Acute heat stress (AHS). (2) Isolation of heat-responsive, microgametogenesis-specific sequences. During our one-year feasibility project, we have accomplished the proposed objectives as follows: Objectrive 1: We have determined the threshold HS conditions in tomato and sorghum. This was essential for achieving the 2nd objective, since our accumulated experience (both Israeli and US labs) indicate that when temperature is raised too high above "threshold HS levels" it may cause massive death of the developing pollen grains. Above-threshold conditions have additional major disadvantages including the "noise" caused by induced expression of genes involved in cell death and masking of the differences between heatsensitive and heat-tolerant pollen grains. Two different types of HS conditions were determined: a) Season-long CMHS conditions: 32/26°C day/night temperatures confirmed in tomato and 36/26°C day maximum/night minimum temperatures in sorghum. b) Short-term AHS: In tomato, 2 hour exposure to 42-45°C (at 7 to 3 days before anthesis) followed by transfer to 28/22±2oC day/night temperatures until flower opening and pollen maturation, caused 50% reduced germinating pollen in the heat-sensitive 3017 cv.. In sorghum, 36/26°C day/night temperatures 10 to 5 days prior to panicle emergence, occurring at 35 days after sowing (DAS) in cv. DeKalb28E, produced starch-deficient and sterile pollen. Objective 2: We have established protocols for the high throughput transcriptomic approach, cDNA-AFLP, for identifying and isolating genes exhibiting differential expression in developing microspores exposed to either ambient or HS conditions and created a databank of HS-responsivemicrogametogenesis-expressed genes. A subset of differentially displayed Transcript-Derived Fragments (TDFs) that were cloned and sequenced (35 & 23 TDFs in tomato and sorghum, respectively) show close sequence similarities with metabolic genes, genes involved in regulation of carbohydrate metabolism, genes implicated in thermotolerance (heat shock proteins), genes involved in long chain fatty acids elongation, genes involved in proteolysis, in oxidation-reduction, vesicle-mediated transport, cell division and transcription factors. T-DNA-tagged Arabidopsis mutants for part of these genes were obtained to be used for their functional analysis. These studies are planned for a continuation project. Following functional analyses of these genes under HS – a valuable resource of genes, engaged in the HS-response of developing pollen grains, that could be modulated for the improvement of pollen quality under HS in both dicots and monocots and/or used to look for natural variability of such genes for selecting heat-tolerant germplasm - is expected.


HortScience ◽  
2019 ◽  
Vol 54 (5) ◽  
pp. 779-782 ◽  
Author(s):  
Jianjun Li ◽  
Xiaoya Lian ◽  
Chenglin Ye ◽  
Lan Wang

Lonicera japonica Thunb., known as Japanese honeysuckle or golden-and-silver honeysuckle, belongs to the honeysuckle family and is native to eastern Asia, including China, Japan, and Korea. Microscopy, spectrophotometry, colorimetry, and the Royal Horticulture Society of Colorimetric Card (RHSCC) were used to compare and analyze the pigment distribution, content, and color variations in the Yujin 2 and Damaohua cultivars at different developmental stages. There were notable differences in the corolla color and the cross-section color between different developmental stages and different varieties. The lightness (L*), redness (a*), and yellowness (b*) values were calculated for each period for the two cultivars to observe variation trends. The chlorophyll content in the corollas of both cultivars showed declining trends with different rates. The chlorophyll content decreased rapidly from the young period to the two white period, and changed gradually from the two white period to the golden period. Moreover, the carotenoid content declined slightly from the young period to the silver period and rose sharply during the golden period. The ratio of these two pigment contents increased dramatically during the golden period: by 11.51 and 6.53 times in ‘Yujin 2’ and ‘Damaohua’, respectively. There were significant differences in corolla color, cross-section color, and the content of three pigments between the two varieties of honeysuckle. distribution and variation of pigments were the key factors affecting the flower color of honeysuckle. This study provides a basis for the identification and breeding of honeysuckle varieties and lays a foundation for further studies on the function and molecular mechanisms of pigments.


2022 ◽  
Vol 28 (1) ◽  
pp. 92-98
Author(s):  
Cristiane Gonçalves Souza ◽  
Sabrina Maihave Barbosa Ramos ◽  
Silvia Nietsche ◽  
Clivia Carolina Fiorilo Possobom ◽  
Elka Fabiana Aparecida Almeida ◽  
...  

Abstract Adenium obesum (Forssk.) Roem. & Schult., popularly known as desert rose, has become a valuable ornamental plant. In floriculture, the production of hybrids is prioritized. Hence, knowledge on floral biology and sexual reproduction of the target species is fundamental. The objectives of this study were: (1) to test sucrose concentrations and temperatures for in vitro germination of A. obesum pollen grains; (2) to identify the effect of temperature on the viability of A. obesum pollen grains; and (3) to evaluate the viability of pollen grains and stigma receptivity in pre-anthesis, at flower opening, and 72 h post-flower opening in three accessions of A. obesum. A significant relationship between temperatures and sucrose concentrations was observed in the in vitro germination test. The highest percentage of in vitro germination of pollen grains, 39.81%, was observed at an estimated temperature of 26.05 °C. Desert rose accessions maintained in biochemical oxygen demand (BOD) chambers at 30 °C during a 16-h light photoperiod showed faster flowering, and temperatures ≥ 25 °C induced pollen grain viability percentages above 69%. Temperature is one of the most important abiotic factors, influencing mainly in pollen germination, pollen tube growing and in efficiency fertilization. The ICA-wd accession stood out and can be considered a pollen donor in artificial pollination. The stigmas of flowers were receptive from a day before flower opening until three days after. The two parameters presented above, stigma receptivity and pollen viability, allow inferences about the appropriate time for successful pollination and subsequent fertilization in desert roses.


2016 ◽  
Vol 2 ◽  
pp. 15-21
Author(s):  
Ram Bahadur KC ◽  
Bal Krishna Joshi ◽  
Surya Prasad Dahal

Germplasm characterization is an important component of crop breeding program.  In characterizing indigenous beans lablab which is used for vegetables as well pulses in Nepal. Twenty three lablab beans germplasm were evaluated for different qualitative and quantitive physico-morphological charecteristics for two years during 2011 and 2012 at Horticulture Research Station, Malepatan, Pokhara. The germplasm showed considerable variations in most of the qualitative and quantitative traits. Leaf size, vine color, flower color, pod color, pod shape, pod type and seed color varied among the genotypes. Variation was also observed in yield attributing characters eg, pod length and width, 10 fresh pod weight, seeds per pod and 100-seed weight.  Days to 50% flowering ranged from 81 to 130 days indicating the presence of early varieties. Fresh pod weight of 10 pods was ranged from 45.0 g to 162.5 g. Multivariate analysis indicated four groups in these genotypes, among with ML-02 and ML-10 were distinct in comparioson with other genotypes. Simple selection may be considered to develop high yielding, early type varieties from these gentopypes.


1992 ◽  
Vol 60 (3) ◽  
pp. 159-164 ◽  
Author(s):  
Ingrid Frykman ◽  
Bengt O. Bengtsson

SummaryIn seven experiments the segregation ratio in barley plants heterozygous for the waxy-gene was studied. Each experiment entailed the scoring of more than 40000 iodine-stained pollen grains from ten spikes. A significant over-representation of blue pollen grains was found in all experiments, with the segregation distortion (measured as a conversion force) ranging from 0·0063 to 0·0143. The distortion was unaffected by which of two mutations was used and which genetic background the plants had, but was stronger in 1988 than in 1987. Different statistical, methodological and biological explanations of the results are discussed.


Genetics ◽  
2001 ◽  
Vol 158 (4) ◽  
pp. 1773-1783 ◽  
Author(s):  
Antonia Procissi ◽  
Solveig de Laissardière ◽  
Madina Férault ◽  
Daniel Vezon ◽  
Georges Pelletier ◽  
...  

Abstract Mutant analysis represents one of the most reliable approaches to identifying genes involved in plant development. The screening of the Versailles collection of Arabidopsis thaliana T-DNA insertion transformants has allowed us to isolate different mutations affecting male gametophytic functions and viability. Among several mutated lines, five have been extensively studied at the genetic, molecular, and cytological levels. For each mutant, several generations of selfing and outcrossing have been carried out, leading to the conclusion that all these mutations are tagged and affect only the male gametophyte. However, only one out of the five mutations is completely penetrant. A variable number of T-DNA copies has integrated in the mutant lines, although all segregate at one mutated locus. Two mutants could be defined as “early mutants”: the mutated genes are presumably expressed during pollen grain maturation and their alteration leads to the production of nonfunctional pollen grains. Two other mutants could be defined as “late mutant” since their pollen is able to germinate but pollen tube growth is highly disturbed. Screening for segregation ratio distortions followed by thorough genetic analysis proved to be a powerful tool for identifying gametophytic mutations of all phases of pollen development.


2009 ◽  
Vol 31 (1) ◽  
pp. 182-189 ◽  
Author(s):  
Pedro Corrêa Damasceno junior ◽  
Telma Nair Santana Pereira ◽  
Messias Gonzaga Pereira ◽  
Francisco Filho da Silva ◽  
Margarete de Magalhães Souza ◽  
...  

This research was done to study the reproductive system of papaya hermaphrodite plant based on the histochemical nature of pollen grain, stigma receptivity, in vivo pollen grain germination and pollen:ovule ratio. In the histochemical analysis, pollen grains were stained by using Sudan IV and I2KI solution ; the stigma receptivity was assessed by alpha-naphthtyl acetate solution in closed and opened flowers. Pollen germination and pollen tube growing were examined in flower buds near anthesis with 0.1% aniline blue. To estimate the pollen:ovule ratio , anthers from each flower bud were dissected and all pollen grains were counted; ovules were dissected from ovaries and were counted under stereomicroscope. The results indicated that papaya pollen grains are of lipidic nature; the stigmas were receptive before the opening and until 48 hours after opening; the pollen grains germinated and emitted polinic tube before flower opening and the pollen:ovule ratio indicated the predominance of autogamous reproductive system. These results indicate that hermaphrodite papaya trees is preferentially of optional autogamous with cleistogamy.


2018 ◽  
Vol 143 (6) ◽  
pp. 409-417
Author(s):  
Le Luo ◽  
Chao Yu ◽  
Xuelian Guo ◽  
Huitang Pan ◽  
Qixiang Zhang

Rosa laxa is widely distributed in the Xinjiang Uygur Autonomous Region of China and is highly adaptable and rich in variation. In this study, we investigated the morphology, habitats, and palynomorphology of R. laxa botanical varieties from Xinjiang, China. In addition to R. laxa var. laxa, there were three other botanical varieties of R. laxa growing in southern Xinjiang, including var. mollis, var. kaschgarica, and var. tomurensis. Together, these four botanical varieties exhibited morphological variation, mainly in the morphology of prickles and the glandular trichome and in flower color. The pollen grains of the R. laxa botanical varieties, all medium in size (21.77–48.39 μm), came in three shapes: perprolate, prolate, and subspheroidal. Their pollen exine sculptures were characterized by either a striate-perforation pattern or striate pattern, but perforation varied in terms of diameter and density and striae varied in depth and density. Palynomorphological assessment showed that three types of evolution, i.e., primitive, transitive, and evolved, were present among R. laxa botanical varieties, and pollen dimorphism was observed in the same botanical variety. Perprolate pollen with a dense striate pattern was the most evolved type. Based on morphological and palynomorphological investigations, var. tomurensis was considered to be the most evolved one among the studied botanical varieties.


1998 ◽  
Vol 46 (3) ◽  
pp. 199-207 ◽  
Author(s):  
Kalyani Datta ◽  
Subodh Datta K.

Palynological investigation on five cultivars of Chrysanthemun morifolium Ramat. and their induced somatic flower color mutants obtained through gamma irradiation and colchicine treatment has been carried out using LM and SEM. The objective of the work was to analyze the changes in the pollen morphology which occurred in mutagen-induced somatic flower color mutants and to verify if there is any correlation between the changes in flower color/type and pollen morphology. Chromosomal status of all the cultivars and their somatic mutants is hexaploid (6 n = 54), but different types of chromosomal aberrations have been observed. Significant increase in pollen grain sterility was found in all the mutants. The pollen grains of all the cultivars and their mutants are basically 3(-4) zonocolporate with tectate spinose exine having perforations. No appreciable variation in pollen apertural character was noticed in any of the mutants. Significant changes in pollen exine surface pattern were found in 4 mutant varieties. The changes are inconsistent and do not correspond to the intensity of radiation.


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