Paweł Nowaczyk

Effect of selected factors on the effectiveness ofCapsicum annuum L. anther culture

The primary aim of the study was to establish the effectiveness of induced androgenesis inin vitro anther culture of two pepper (Capsicum annuum L.) breeding lines — ATZ1 and PO, and a hybrid between these two lines (ATZ1 × PO)F1. Anther culture was maintained according to the method developed by Dumas de Vaulx et al. (1981) with some modifications. The experiment revealed that the effectiveness of androgenesis ranged from 4% for the ATZ1 line to 1.5% for the (ATZ1 × PO)F1 and strongly depended on the developmental stage of flower buds, as well as the conditions for anther culture maintenance. The development of androgenic embryos was successfully induced only in anthers which originated from the flower buds with petals equal or slightly longer than sepals and there was a clear relationship between the length of the period of anther induction on CP medium and the level of kinetin in R1 regeneration medium.

Induced androgenesis of Capsicum frutescens L.

The aim of the research was to make a preliminary determination of the effectiveness of the induction of haploids in Capsicum frutescens L. In order to induce androgenesis red and yellow fruit forms of species were used, each bred by the researchers on their own. The experiment was performed in October. Anther cultures were conducted according to a modified method developed by Dumas et al. (1981) for C. annuum L. The anthers were laid on CP medium containing 0.01 mg dm−3 2.4-D and 0.01 mg dm−3 kinetin, with the addition of 0.5 g dm−3 of activated carbon and 5 mg×dm−3 of silver nitrate, solidified with 8 g dm−3 of agar. The cultures were incubated in the dark at 35 deg C for 8 days. Next they were transferred to 25 deg C under a 12-hour photoperiod. After 14 days of induction, anthers were transferred to R1 medium supplemented with 0.1 mg dm−3 kinetin. Obtained embryos were subsequently transplanted onto V3 hormone-free medium and well growing plants were planted in greenhouses. The efficiency of androgenesis for both C. frutescens L. forms was relatively low and it did not exceed 5%. The ploidy level of the resulting plants was determined by flow-cytometric analysis. The regenerants consisted of about equal numbers of haploids and diploids. Additionally, among plants regenerated from anthers of yellow fruit forms, two mixoploids were observed.

The assessment of doubled haploid lines obtained in pepper (Capsicum annuum L.) anther culture

Abstract The aim of the research was the analysis of 11 DH-R2 pepper (Capsicum annuum L.) lines, obtained in anther cultures of ‘(ATZ1 × PO)’ F1, ‘(ATZ1 × CDT)’ F1 and ‘(ATZ1 × TG)’ F1 hybrids. To determine the genetic homogeneity of anther-derived lines, the biometrical characteristics of fruits, as well as fruit colour and shape inheritance, were analysed. The biometrical analysis determined the highest phenotype uniformity in androgenic lines of ‘(ATZ1 × PO)’ F1. Based on the fruit shape and colour variation, it was possible to determine the microspore origin of androgenic diploids obtained in anther cultures of ‘(ATZ1 × TG)’ F1. Additionally, enzyme analysis of four isozymes (PGM, PGI, IDH and MDH) showed that isocitrate dehydrogenase identified anther-derived diploids of hybrids between ‘ATZ1’ and ‘TG’, as well as those between ‘ATZ1’ and ‘CDT’, lines.

Study of individual plant responsiveness in anther cultures of selected pepper (Capsicum spp.) genotypes

Abstract One of the key factors determining the effectiveness of pepper anther cultures is donor plant genotype. The stock material for androgenic embryos inductions is usually made up of hybrid forms, since the higher the degree of heterozygosity, the greater the chances of producing regenerates with unique genotypes. The aim of the presented research was to evaluate individual plant reaction in anther cultures for the C. annuum hybrid (‘ATZ1’ × ‘TG’)F2, interspecific hybrid (C. frutescens × C. chinense)F2 and androgenic DH line AT6. The effectiveness of androgenesis was determined individually for each plant as the percentage of the embryos produced compared to the total number of anthers cultured. In the hybrid (‘ATZ1’ × ‘TG’)F2, anthers of 19 out of 20 plants evaluated produced embryos at a rate of 0.5 to 16.5%. Anthers of the AT6 DH line formed embryos considerably less frequently. A positive reaction was recorded for 13 out of 20 plants and the effectiveness of androgenesis did not exceed 3% for this genotype. The lowest androgenic response was recorded for the hybrid (C. frutescens × C. chinense)F2, where embryo development was observed in only five out of 19 plants and the effectiveness of androgenesis did not exceed 2%. The ploidy level of the regenerates was defined cytometrically. The analysis revealed the presence of haploid and diploid plants among the regenerates of all the genotypes evaluated.

Androgenic response of Capsicum interspecific hybrids and capsaicinoid characteristics of DH lines

Summary In the research on induced androgenesis, eight groups of plants, the progeny of interspecific hybrid of Capsicum frutescens L. x C. annuum L., were used. Half of them were standard hard-flesh forms, while the others have represented SS or Ss genotype conditioning the soft flesh of ripe fruit. Anthers from the plants of six groups produced mixoploid callus and the DNA content ranged from 1C to 16C. Three groups formed embryos which converted into plants. The total number of regenerants was 19, included both androgenic haploids (13) and diploids (6). The results did not allow to present the simple relationship between the physiological feature of soft-flesh and the effectiveness of androgenesis. Pungent, soft-flesh genotypes appeared as a poor responsive in anther culture. The R2 and R3 generation of two soft-flesh diploids, evaluated in two-year experiments, showed full phenotypic uniformity, proofing the androgenic origin of diploids. These DH lines were different with regard to capsaicinoid profiles. The content of capsaicinoids ranged from 0.056 to 2.170 and from 0.019 to 1.610 g*kg-1 for capsaicin and dihydrocapsaicin, respectively. The highest concentration of the compounds was observed in the placenta. Although the androgenic effectiveness was not fully satisfactory, the doubled haploid technology can be used for the rapid genetic stabilization of soft-flesh Capsicum spp. recombinants and the special attention should be paid to the spontaneous androdiploids.

Relationship between Technological Characters in Capsicum SPP. Soft-Flesh Forms

Relationship between Technological Characters in Capsicum SPP. Soft-Flesh Forms The present research involved the evaluation of relationships between technological characters of soft-flesh fruit in the lines derived from the hybrid Capsicum frutescens L. × C. annuum L. The evaluation was performed in groups of genotypes which differed in their fruit weight and pericarp thickness. The material researched was made up of the pericarp from which placenta with seeds was removed and the puree obtained as a result of whole fruit crushing. The analysis of the content of capsaicinoids was made using the HPLC method. The content of capsaicin was in each case higher than that of dihydrocapsaicin. There were observed highly significantly positive correlations between the average fruit weight and the wall thickness in the genotypes of a higher level of these characters, namely in the groups over 20 g (fruit weight) and over 3 mm (wall thickness). In these groups the content of capsaicinoids was negatively correlated with the average fruit weight. The significance of this relationship was confirmed in the genotypes of a higher fruit weight as compared with the content of capsaicin and dihydrocapsaicine in the puee. The relationships between the capsaicinoids researched were more stable in the genotypes of a higher fruit weight and demonstrating a higher pericarp wall thickness. Współzależność Cech Technologicznych u Form Soft-Flesh Capsicum SPP. Przedmiotem opracowania była ocena zależności między cechami technologicznymi owoców soft-flesh u linii wyprowadzonych z mieszańca Capsicum frutescens L. × C. annuum L. Dokonano jej w grupach genotypów różniących się masą owocu oraz grubością owocni. Badanym materiałem była owocnia, z której usunięto łożysko z nasionami oraz przecier uzyskany w wyniku rozdrobnienia całych owoców. Analizy zawartości kapsaicynoidów wykonano metodą HPLC. Zawartość kapsaicyny była w każdym przypadku wyższa niż dihydrokapsaicyny. Obserwowano wysoce istotnie dodatnie korelacje między średnią masą owocu a grubością ścian u genotypów o wyższym poziomie tych cech, to jest w grupach powyżej 20 gram (masa owocu) i powyżej 3 mm (grubość ścian). W wymienionych grupach zawartość kapsaicynoidów była ujemnie skorelowana ze średnią masą owoców. Istotność tej relacji potwierdzono u genotypów o większej masie owocu w odniesieniu do zawartości kapsaicyny i dihydrokapsaicyny w przecierze. Zależności między badanymi kapsaicynoidami były bardziej stabilne u genotypów o większej masie owoców i charakteryzujących się większą grubością ścian perykarpu.

Biometrical Assessment of Interspecific Hybrids of Capsicum Genus

Biometrical Assessment of Interspecific Hybrids of Capsicum Genus The F1 hybrids obtained as the result of interspecific crosses: C. annuum x C. frutescens, C. frutescens x C. annuum, C. frutescens x C. chinense and C. chinense x C. frutescens were analysed biometrically. The plants were cultured in unheated foil tent. Yield and the number of fruit from plant were qualified. For ten plants of each of the hybrids detailed fruit analysis were performed. The tested traits were: weight of fruit, length, width, technological weight and weight of pericarp, pericarp thickness, the weight of placenta without seeds, the weight of dry seeds and the dry matter content. The analysis of variance was conducted on the obtained results. The tested hybrids were characterised by the large differentiation of the estimated characters. The hybrids obtained from crosses: C. annuum x C. frutescens and C. frutescens x C. annuum seem to be the most valuable material for the future pepper breeding work. Fruits of these hybrids combine high weight, typical for cultivated forms of C. annuum with increased dry matter content characteristic for C. frutescens. These materials will be used as the parental forms of homozygous lines which possess traits valuable in genetic improvement of pepper. Ocena Użytkowa Mieszańców Międzygatunkowych Z Rodzaju Capsicum Ocenie biometrycznej poddano mieszańce pokolenia F1 otrzymane w wyniku krzyżowań oddalonych: C. annuum x C. frutescens, C. frutescens x C. annuum, C. frutescens x C. chinense i C. chinense x C. frutescens. Uprawę roślin prowadzono w nieogrzewanym tunelu foliowym. Określono plon i liczbę owoców z uzyskanych mieszańców. Owoce dziesięciu wybranych roślin każdego genotypu, poddano szczegółowej ocenie biometrycznej. Oznaczono: masę owocu, długość, szerokość, masę technologiczną i biologiczną, grubość ścian, masę łożyska bez nasion, masę nasion suchych oraz suchą masę owocu. Wyniki poddano analizie statystycznej stosując jednoczynnikową analizę wariancji. Stwierdzono, że badane mieszańce charakteryzowały się dużym zróżnicowaniem pod względem ocenianych parametrów. Na szczególną uwagę w dalszych pracach hodowlanych zasługuje materiał pochodzący z krzyżowań: C. annuum x C. frutescens i C. frutescens x C. annuum. Owoce tych mieszańców łączą wysoką masę, typową dla uprawnych form C. annuum, z podwyższoną zawartością suchej masy, charakterystyczną dla C. frutescens. Materiały te posłużą jako formy wyjściowe do uzyskania homozygotycznych linii, łączących te pożądane właściwości, przydatne w genetycznym doskonaleniu papryki rocznej.

The effect of growth regulators on tomato (Lycopersicon esculentum) fertility.

The aim of the study was to determine the effect of 2,4 D (2,4dichlorophenoxyacetic acid) used separately and in a mixture with BAP (benzylaminopurine) on fertility and some features of tomato fruit. The plant flowers were immersed only once in water solutions of the growth regulators (2,4 D 0.001 %; 0.005 %; 2,4 D 0.001 % + BAP 0.001 %; 2,4 D 0.005 % + BAP 0.005 %). The mean fruit weight, fruit volume, specific weight, and the jelly weight were determined. The number of seeds collected from the fruit was used as a criterion of fertility estimation. No statistically significant differences were found in the mean fruit weight, fruit volume and specific weight. The fruits derived from the plants which were not exposed to the action of growth regulators were characterized by the smallest amount of jelly while the fruits set under the influence of 0.001 % 2,4 D + 0.001 % BAP had the largest jelly amount. The greatest differentiation was found in fertility which ranged from 7.5 seeds from the fruit derived from the plants treated with 0.005 % 2,4 D, to 75.7 seeds from the non-treated plants’ fruit. The BAP addition caused the limitation of fertility reduction.