Genotype, environment and their interaction effects on olive tree flowering phenology and flower quality

Abstract

Flowering is one of the most critical processes in the reproductive phenology in fruit trees including olive. Under Mediterranean climate, olive flowering period normally occurs in late spring or early summer. Therefore, flowering could be affected by adverse environmental conditions as water stress and high temperature, thus influencing flower quality. Previous works have demonstrated the effect of genotype and environment on olive flowering, but those factors has never been compared in a single study nor their interaction has been evaluated. In the present work, we used multi-environment trial stabilised in with four different agro-climatic conditions of Andalucía, Southern Spain, to test the genetic and environmental influence on flowering timing (flowering period, full bloom period, and full bloom date) and flower quality (flower number, perfect flower number and flower number percentage). Most of the variability found for flowering phenology parameters was due to environmental influence. On the contrary, for flowering quality parameters, most of the variability was of genetic nature. In all cases, the genotype-environment interaction was significant. In this sense, the GGE biplot model used to analyse the interaction showed that most of the genotypes evaluated have low stability for most of the parameters evaluated. Those results emphasize the benefits of multi-environment trials on olive in order to select the best genotype adapted to different environments and as a tool to face the future variability of environmental conditions caused by the climate-warming scenario.

Differences on flowering phenology under Mediterranean and Subtropical environments for two representative olive cultivars

“…For each location and year, four trees of 'Arbequina' and 'Picual' cultivars, aged from 7 to 9 years and with significant amount flowering were chosen for the study to avoid the potential effect of yield on phenology. Amount of flowering was evaluated following a previously reported methodology (Navas-Lopez et al, 2019) in a 0-3 scale (0 = no flowering, 1 = less than 33 % of the canopy having flowers, 2 = from 33 to 66 % of the canopy flowered and 3 = more than 66 % of the canopy flowered). Phenology was evaluated in three consecutive years from 2016 to 2018 except 'Picual' at El Viso in 2016 and Los Tomillos in 2017 and 2018.…”

“…Observations started when stage 53 appeared (inflorescence buds open and lower cluster development are visible) and ended when stage 69 was the most common in the tree (end of flowering, fruit set, non-fertilized ovaries fallen). Twice a week, the earliest, most common and latest stages were recorded for each tree and location after visually inspection of the whole canopy, as standard protocol on olive (Navas-Lopez et a., 2019;Vuletin-Selak et al, 2013).…”

“…Flowering is a critical reproductive stage for the final yield in many plant species (Díez-Palet et al, 2019), being highly influenced by climatic conditions (Rodríguez et al, 2019). This included olive (Hartmann and Porlingis, 1957;Navas-Lopez et al, 2019), an evergreen fruit species typical from Mediterranean climate. For that reason, climatic models have been developed to forecast the flowering date in olive, mainly based on air temperature (De Melo-Abreu et al, 2004;Gabaldón-Leal et al, 2017).…”

Floral Quality Characterization in Olive Progenies from Reciprocal Crosses

“…Pistil abortion is influenced by environmental and nutritional conditions [ 14 , 15 , 16 , 17 ]. Furthermore, as also occurs in other species in the plant kingdom [ 18 ], this trait has a clearly recognizable genetic component in olive trees [ 9 , 11 , 19 , 20 , 21 , 22 ].…”

Karakterisasi Morfologi dan Fenologi Pembungaan Dua Aksesi Kopsia pauciflora Hook.f. Bunga Putih dan Merah Muda di Kebun Raya Purwodadi, Jawa Timur

“…Informasi mengenai periode berbunga pada setiap tanaman dapat digunakan untuk menentukan waktu terbaik melakukan hibridisasi (Farida dan Ardiarini 2019). Data perkembangan Proses pembungaan pada dasarnya merupakan interaksi dari pengaruh faktor eksternal yaitu suhu, cahaya, kelembapan, curah hujan, dan unsur hara serta faktor internal yaitu genetik dan hormon (Nurtjahjaningsih et al 2012;Yang et al 2016;Singh et al 2018;Navas-Lopez et al 2019). Ketika tanaman mendapatkan kondisi lingkungan optimum maka tanaman akan menghasilkan bunga.…”