Precipitation during anthesis reduces seed set in perennial ryegrass

Abstract

In perennial ryegrass seed production, the establishment of seed yield potential occurs until the point of anthesis. However, utilizing potential seed yield is predominately focused on processes after anthesis, namely seed set (%) and seed filling. In practice, seed yield is the product of the number of harvested seeds remaining after cleaning and average seed weight. For this study, the anthesis patterns and seed set were recorded in a diploid variety grown in seed production fields in three different Danish regions with contrasting weather conditions and investigated in 2013 and 2014. Increases in the total precipitation during anthesis reduced the anthesis synchrony and the seed set, which ranged from 50% to 66%. Under semi-controlled environmental conditions in which the influence of precipitation was excluded, the seed set was found to be influenced by the floret position in the spikelet and ranged from 73% in the florets in basal positions to 25% in the distal florets. It is suggested that a lower number of florets per spikelet will reduce the anthesis period.These results may provide insights for breeding programmes focused on increasing seed yield.breeding, climate, flowering, rainfall, spikelet, synchrony | INTRODUCTIONPerennial ryegrass (Lolium perenne L.) seed production is determined by genetics, the environment and management practices. Seed producers are able to control two of these factors by selecting and determining the best management strategy for the genetic material grown; however, they have little to no control over the environment, which influences both the development and utilization of the seed yield potential.Seed set is an important factor in the effective utilization of the seed yield potential and the resulting seed yield. Marshall and Wilkins (2003) showed that a positive relationship occurs between the seed set and seed yield per inflorescence in a range of perennial ryegrass varieties grown under field and glasshouse conditions. However, Hampton and Hebblethwaite (1983) and Elgersma, Stephenson, and den Nijs (1989) suggested that low seed yield can be partially attributed to environmental limitations during the anthesis process, with low floret site utilization, which is defined as the percentage of florets that produce a seed, caused by low fertilization efficiency.Anthesis, pollen dehiscence, pollen viability and stigma receptivity are influenced by a number of environmental parameters. In a comprehensive review, Hill (1980) described the environmental conditions that either promote or inhibit anthesis in a range of grass species. Temperature, light intensity and precipitation are important to anthesis and pollen dehiscence in perennial ryegrass. Hill (1980) noted that day temperatures of at least 18°C are required on the day of anthesis, night temperatures of 10°C advance both the start of anthesis and peak anthesis and day temperatures below 14°CThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permi...

Effects of nitrogen fertilisation and irrigation on seed yield and yield components of signal grass (Urochloa decumbens)

“…Irrigation was discontinued after flowering on the basis of previous research (Lambert 1967;Cookson et al 2000). In coolseason perennial grasses, many of the studies on irrigation (Lambert 1967;Hebblethwaite 1977;Chastain et al 2014) and precipitation during anthesis (Abel and Boelt 2018) suggested that wet weather and amount and timing of precipitation could depress pollination, as well reduce yield-component development. Nitrogen as granular ammonium nitrate (340 g N kg -1 ) was spread manually on the soil surface at the appropriate rates for the subplots receiving 25, 50 and 75 kg N ha -1 on 30 October 2009 (21 days after mowing for the first crop) and 25 February 2010 (20 days after mowing for the second crop).…”

Macroevolutionary history predicts flowering time but not phenological sensitivity to temperature in grasses

“…This ‘reproductiveCondition’ data was entered into the UBC database, following DarwinCore standards (Wieczorek, 2012). We focused on anthesis, as this is an identifiable phenological stage that occurs for a limited duration of time (Abel and Boelt, 2018)— Lolium perenne L. for example, is typically in anthesis for less than three weeks. Note that for simplicity, we refer to anthesis as flowering in the remainder of the manuscript.…”

Precipitation controls seed bank size and its role in alpine meadow community regeneration with increasing altitude

“…Arroyo, Chacon, and Cavieres (2006) found that changes in precipitation are closely related to seed longevity and directly reduce the seed density in the soil seed bank. Decreased precipitation affects the flowering period of plants, reducing their fruiting rate (Abel & Boelt, 2017).…”

“…Arroyo, Chacon, and Cavieres (2006) found that changes in precipitation are closely related to seed longevity and directly reduce the seed density in the soil seed bank. Decreased precipitation affects the flowering period of plants, reducing their fruiting rate (Abel & Boelt, 2017). In contrast, increased precipitation has been found to promote sexual reproduction in all species studied (Cleland et al., 2013) and increase the size of the seed bank through seed input.…”