Impacts of high temperature on embryonic growth and seed germination of dill (Anethum graveolens)

Abstract

Temperature is the main exogenous factor that determines the growth, development and productivity of agricultural plants, including seed germination. In this work, we studied the thermosensitivity of heterogeneous dill seeds (Anethum graveolens). The study aimed to study the short-term (1-5 days) effect of high temperature (40°C) on the growth of the embryo and germination of dill seeds formed on different umbels of the mother plant. The growth of the embryo had a significant effect on seed germination (r = 0.976; P < 0.001). Seeds collected from primary umbels have a more developed embryo and can overcome the effects of thermal stress. We also found that the duration of heat exposure at 40°C, leading to a decrease in viability, can vary from 1-5 days for seeds from primary umbels, to 1-2 days for seeds from secondary umbels, which, in our opinion, is due to the heteromorphism. The influence of the place of seed formation on the mother plant and the high temperature during germination is critical for embryo growth and dill seeds’ germination.

Aerobic Rice (Cv. MRIA) Differs Temporarily by Environmental Stress during Seed Development and Maturation

“…Those plants were treated with the combination of stresses (HT+WL) for 7 consecutive days exposure. This present finding is similar with a study conducted by Martinez-Eixarch and Ellis [36], which reported that seed viability was most vulnerable by 7 days of exposure to high temperature (38C) in the 7 or 14 DAA, when histodifferentiation occurs. During seed development, seed are in the process into filling with its composition and this is influenced by various metabolic processes.…”

“…This low viability after mother plant stress is supported by Martínez-Eixarch and Ellis [35] who reported that the viability of Gleva seeds was reduced by extreme-temperature (38/34℃) treatments applied in the 7 or 14 d immediately after anthesis. Similarly, another study conducted by Bukharov et al [36] reported that the duration of heat at 40°C may lead to a decrease in viability of dill (Anethum graveolens) which vary from 1-5 days of exposure.…”

Effect of Cutting Treatment on Seed Yield and Seed Quality of Dill

“…According to Bukharov et al (2021) who studied the short-term (1-5 days) effect of high temperature (40°C) on the growth of the embryo and germination of dill seeds, the degree of development of the embryo determines seed germination. The reported results showed that the less developed embryos in seeds from secondary umbels are more sensitive to high temperatures during dill seed germination.…”

“…In both seasons, high and low soil temperatures cause failure of field emergence or irregular emergence in this species that is grown by direct seeding and that has a long field emergence period, resulting in product loss (Zehtab-Salmasi et al, 2006;Ghassemi-Golezani et al, 2018). In addition, there have been reports about problems with the quality of the produced dill seeds, such as poor germination and slow and heterogeneous field emergence (Bukharov et al, 2021;Alan et al, 2022).…”

“…Especially climate conditions (maximum and minimum temperature, precipitation, humidity) in the period that starts with flower formation and continues with pollination, fertilization, and seed maturation affect seed quality and yield (Singh et al, 2013). It has also been shown that dill seed yield and quality was affected by some factors such as weather conditions, irrigation, seed harvest time (Zehtab-Salmasi et al, 2006;Ghassemi-Golezani et al, 2018;Alan et al, 2022), seed stalk architecture, disease and pests (Bralewski et al, 2005;Dorota and Bralewski, 2006;Holubowicz and Morozowska, 2011), umbel position (Bukharov et al, 2021). To the best of our knowledge there have been no studies to date investigating the effects of cutting on seed quality in dill, although it was reported that cutting decreased seed yield (Moustafa et al,1990;Osman and El-Wahab, 2009).…”