Assessment of the Genetic Distinctiveness and Uniformity of Pre-Basic Seed Stocks of Italian Ryegrass Varieties

Abstract

Lolium multiflorum Lam., commonly known as Italian ryegrass, is a forage grass mostly valued for its high palatability and digestibility, along with its high productivity. However, Italian ryegrass has an outbreeding nature and therefore has high genetic heterogeneity within each variety. Consequently, the exclusive use of morphological descriptors in the existing varietal identification and registration process based on the Distinctness, Uniformity, and Stability (DUS) test results in an inadequately precise assessment. The primary objective of this work was to effectively test whether the uniformity observed at the phenological level within each population of Italian ryegrass was confirmed at the genetic level through an SSR marker analysis. In this research, using 12 polymorphic SSR loci, we analyzed 672 samples belonging to 14 different Italian ryegrass commercial varieties to determine the pairwise genetic similarity (GS), verified the distribution of genetic diversity within and among varieties, and investigated the population structure. Although the fourteen commercial varieties did not show elevated genetic differentiation, with only 13% of the total variation attributable to among-cultivar genetic variation, when analyzed as a core, each variety constitutes a genetic cluster on its own, resulting in distinct characteristics from the others, except for two varieties. In this way, by combining a genetic tool with the traditional morphological approach, we were able to limit biases linked to the environmental effect of field trials, assessing the real source of diversity among varieties and concretely answering the key requisites of the Plant Variety Protection (PVP) system.

Genetic structure of the collection of ryegrass (Lolium) cultivars: a study based on SSR and SCoT markers

“…6). при этом показатель гетерозиготности в среднем по каждои� из используемых систем приближался к 0,23, что оказалось значительно ниже значении� , определенных в работе E. Pasquali с соавторами (Pasquali et al, 2022). Исследователи анализировали по 47 индивидуальных генотипов от каждого из 14 сортов раи� граса пастбищного с применением микросателлитных маркеров и обнаружили, что параметры эффективного числа аллелеи� и ожидаемои� гетерозиготности составляли в среднем 19,9 и 0,65 соответственно.…”

“…Для генотипирования популяции� и образцов разных видов раи� граса применяются как доминантные (RAPD, AFLP, SRAP, ISSR), так и кодоминантные маркеры (SSR и SNP) (Kubik et al, 2001;Wang et al, 2009;Liu et al, 2018;Pasquali et al, 2022). В нашеи� работе при оценке генети-ческои� изменчивости сортов пастбищного и однолетнего раи� граса использовали полиморфные микросателлитные локусы (SSR -Simple Sequence Repeats) и относительно новую систему SCoT-маркеров (SCoT -Start Codon Tar geted Polymorphism), разработанных на основе выявления различии� в коротких консервативных участках, фланкирующих ATG-стартовыи� кодон в генах растении� (Collard, Mackill, 2009).…”

Morpho-phytochemical screening and molecular diversity of pomegranate accessions grown in Halabja Governorate, Kurdistan Region-Iraq

“…Therefore, morphological criteria alone are not su cient to distinguish some different varieties that are morphologically similar. Therefore, the molecular ngerprinting of a plant variety is extremely important for protecting plant breeders' rights (Pasquali et al 2022).…”

N2 Use in Perennial Swards Intercropped with Young Poplars, Clone I-214 (Populus × euramericana (Dode) Guinier), in the Mediterranean Area under Rainfed Conditions

“…In Italy, among the most used perennial forage crops, the Italian ryegrass (Lolium multiflorum Lam.) is one of the most appreciated and employed as forage and pasture crops due to its high productivity and high nutritional value as livestock feed [44]. Also, sulla (Hedysarum coronarium L.), a typical biennial legume widely grown in Central and Southern Italy, could be particularly beneficial for: (i) its capability to exploit clay and alkali soils under rainfed conditions and (ii) its high nutritive value as pasture and hay, mostly due to its high protein content [45].…”