Agro-morphological and molecular assessment of doubled haploid lines of pepper (Capsicum annuum L.)

Abstract

Celem badań była ocena agromorfologiczna i molekularna pokoleń R3 ośmiu linii DH papryki (Capsicum annuum L.), otrzymanych w kulturach pylników mieszańców międzyodmianowych (ATZ1xPO)Fj oraz (ATZ1xCDT)Fr Opracowanie statystyczne wyników biometrycznych wykazało zróżnicowanie między badanymi formami, a także bardzo dużą jednorodność fenotypową w obrębie pojedynczej linii. Na szczególną uwagę zasługiwały linia AP10, plonująca na poziomie formy matecznej ATZ1, oraz linia AP15, która przewyższała pod tym względem obydwie formy rodzicielskie. Oceniane linie DH poddano analizie molekularnej za pomocą PCR-RAPD. Osiem starterów generowało produkty polimorficzne, co pozwoliło na rozróżnienie wszystkich ocenianych w doświadczeniu linii. Na podstawie otrzymanych elektroforogramów obliczono współczynniki dystansu genetycznego oraz opracowano dendrogramy ilustrujące zróżnicowanie genetyczne między formami rodzicielskimi i potomnymi liniami DH. Wyróżnione pod względem cech użytkowych linie AP10 i AP15 stanowiły wspólną grupę o najmniejszym współczynniku dystansu genetycznego.The aim of the research was the agro-morphological and molecular analysis of eight DH-R3 lines of pepper (Capsicum annuum L.). The following lines of C. annuum were used in the research - three parental forms: ATZ1, PO, CDT, and R3 generation of DH lines obtained in anther culture of two hybrids (ATZ1xPO)F1: lines AP1, AP2, AP10, AP15, AP32, AP40 and (ATZ1xCDT)F1: lines AC5, AC7. The seeds of R1 androgenic plants were used to obtain two further generations of regenerants. The assessment of the homogeneity of the DH-R3 lines was performed with the use of analysis of variations of the important biometrical traits of plants and fruits. Analysis of variance proved homogeneity of all the examined DH populations and Scheffe's test confirmed polymorphism between the lines of a common origin. The following lines deserved special attention: AP10 line - yielding at the level of the maternal form, and AP15 line, which surpassed both parental forms regarding yield level. Additionally, fruits of these two lines were characterized by thick pericarp and high content of dry matter. As biometrical characteristic of the agronomical traits do not always allow a clear identification of androgenic lines, a RAPD analysis was also performed. Genomic DNA of the tested lines was isolated from young leaves of healthy, adult plants. PCR was conducted according to Ilbi. 13 starters were used, which generated between 5 and 11 products of the size varied between 250 and 2350 base pairs. Reactions conducted with the use of the following starters: A01, A07, A10, A11, B10, E19, F05 and F10 generated between one and three polymorphic stripes, which allowed to distinguish and assess the similarity of all the examined lines. The coefficient of genetic distance for the tested lines was calculated using Nei and Li formula in Treecon. Dendrograms illustrating genetic diversity between the lines revealed similar genetic profile of both tested DH lines in the AC line group that displayed resemblance to the maternal ATZ1 line. In the AP group, AP32 and AP40 lines had a similar genetic profile to the maternal ATZ1 form, while AP1 and AP2 lines resembled the paternal form, PO line. AP10 and AP15 lines, previously distinguished with regards for the biometrical traits, comprised a common group of the lowest coefficient of genetic distance