Efficient seed storage is a shared concern among the growing number of seed banks established for crop improvement or ex situ conservation. Container properties greatly affect seed interactions with the environment and the overall cost and success of seed banking operations. Several material properties contribute to their suitability as seed containers. This paper provides a consolidated list of water vapour permeability properties of thermal plastics commonly used for packaging. Composite packages with layers of film with different properties provide distinct advantages to seed banks. Different seed banks must rank the importance of the various factors depending on their mission and resources. Once the risks, costs and benefits are weighed, an appropriate strategy can be developed that addresses a seed bank's specific needs. Because there are many problems and several solutions, it is likely that strategies will vary among seed banks. This response details variables to consider when selecting seed storage packages, and focuses on water diffusion rates of packages with different compositions. A ‘moisture audit’ will help seed bank operators make informed decisions about packaging.

Cotton (Gossypium spp.) is an important source of edible oil and protein meals. Complex genetics and strong environmental effects hinder progress in seed quality trait breeding in this species. The use of molecular markers can improve an understanding of the genetic factors conditioning seed quality traits, and is expected to assist in selection of superior genotypes. This study was conducted to identify quantitative trail loci (QTL) associated with seed physical and nutrient traits in cotton. To achieve this objective, a population of 140 BC1S1 lines developed from a cross between ‘TM-1’ and ‘Hai7124’ was evaluated in 2003 and 2004. A linkage map consisting of 918 markers from this population was used to identify QTL using QTLNetwork-2.0 software. Eleven single QTL were identified for kernel percentage, kernel oil percentage, kernel protein percentage and seven amino acids (Asp, Ser, Gly, Ile, Leu, Phe and Arg). Phenotypic variation explained by each individual QTL ranged from 10.89 to 46.28%. Two epistatic QTL for Cys and Leu were detected, explaining 9.55 and 4.43% of the phenotypic variation. These QTL detected for seed quality traits in cotton are expected to be useful for further breeding programmes targeting development of cotton with improved nutrient quality.

Red rice (Oryza sativa L.) dispersal units (florets) were dry-afterripened for 0–8 weeks and subsequently incubated at 30°C in polyethylene glycol (PEG) solutions with water potentials from 0 to − 1.6 MPa. Germination percentages and rates increased with dry-afterripening and water potential of the incubation medium. The seed population exhibited a normal distribution of base water potentials (Ψb, i.e. minimum water potential allowing germination) among individual seeds, characterized by three parameters: the hydrotime constant (θH), the mean base water potential (Ψb) and the standard deviation of the base water potential distribution (σΨb). Changes in germination during afterripening could be described by modifications of such parameters, particularly Ψb, which was employed to derive an index, DH(ARX = Ψb(ARX) − Ψb(ARN), where DH(ARX) represents a measure of dormancy of the seed population (in MPa) based on the hydrotime model, Ψb(ARX) is the mean base water potential of the seed population at any afterripening time X, and Ψb(ARN) is the mean water potential of the non-dormant (fully afterripened) population. The introduction of this index permitted interpretation of afterripening as a measurable reduction in the dormancy status of the seed, with progressive acquisition of both full germinative capacity and maximum germination rate, as anticipated by the hydrotime model. Moreover, secondary dormancy was induced proportionally to the reduction in water potential in the dark. Susceptibility to secondary dormancy induction was defined through DI(ARX), an index analogous to DH(ARX). These indices revealed that, in red rice, both breaking of primary dormancy and the inducibility of secondary dormancy followed decay kinetics with different sensitivities to the duration of dry storage.

Orthodox, desiccation-tolerant seeds lose desiccation tolerance during germination. Here, we quantify the timing of the loss of desiccation tolerance, and explore the implications of this event for seed mortality and the shape of germination progress curves for pioneer tree species. For the nine species studied, all seeds in a seedlot lost desiccation tolerance after the same fixed proportion of their time to germination, and this proportion was fairly constant across the species (0.63–0.70). The loss of desiccation tolerance after a fixed proportion of the time to germination has the implication that the maximum number of seeds in a seedlot that can be killed by a single drying event during germination (Mmax) increases with an increasing time to 50% germination (t50) and an increasing slope of the germination progress curve. Consequently, to prevent the seed population from becoming highly vulnerable to desiccation-induced mortality, species with a greater t50 would be expected to have a shallower germination progress curve. In conclusion, these data suggest that the loss of desiccation tolerance during germination may constitute a significant, but previously unexplored, source of mortality for seeds in seasonal environments with unpredictable rainfall.

Germination and dormancy breaking requirements were studied in Selinum carvifolia (L.) L. and Angelica sylvestris L. (Apiaceae). Seeds of these two species have an underdeveloped embryo and are morpho-physiologically dormant. The embryo does not start to grow until physiological dormancy is broken by cold stratification. Incubating seeds at fluctuating temperatures in the light, after cold stratification, had a stimulating effect on embryo growth and seed germination. Seeds of S. carvifolia and A. sylvestris have non-deep simple morphophysiological dormancy (MPD), since gibberellic acid (GA3) could substitute for cold stratification. This is the first report of non-deep simple MPD that is broken by cold stratification in the Apiaceae. Under natural conditions, physiological dormancy is broken by low temperature conditions during winter. Embryo growth and germination occur in a short time interval when temperatures start rising in early spring. Due to the fact that multiple environmental signals regulate dormancy, seedling emergence in these species is timed very accurately in spring.

Rudimentary, broad and small linear embryos occur among members of the most primitive (basal) extant angiosperms, collectively called the ANITA grade (i.e. Amborella, Nymphaeales and Austrobaileyales). Amborella (rudimentary) and Austrobaileyales (rudimentary in Austrobaileyaceae, Illiciaceae and Schisandraceae and small linear in Trimeniaceae) have kinds of embryos that are known to be underdeveloped; consequently, they must grow inside the seed prior to radicle emergence (germination). On the other hand, it is not known if broad embryos need to grow before radicles can emerge, and whether they are underdeveloped or fully developed. Thus, we addressed the question: ‘Is the broad embryo of Nymphaeales also underdeveloped?’. Although the embryo length : seed length ratios in Nymphaea Albert Greenburg, N. capensis var. zanzibariensis and N. immutabilis were 0.311, 0.349 and 0.234, respectively, embryos did not grow prior to radicle emergence. Thus, they are fully developed at seed maturity. If Amborella and Nymphaeales are equally the most basal angiosperms, as some molecular phylogenetic studies indicate, then we must conclude that the broad and rudimentary embryos are equally primitive.

LEAFY (LFY)-like proteins are plant-specific transcription factors that play essential roles in plant growth and development. In this study, a LEAFY homologue in soybean [Glycine max (L.) Merr.], designated as GmLFY, was cloned from inflorescences by the rapid amplification of cDNA ends (RACE) method. Sequence analysis showed that GmLFY cDNA contained a 1221 bp open reading frame, encoding 407 amino acid residues with typical characteristics of transcription factors. Subcellular localization in onion epidermal cells indicated that GmLFY protein was located in the nucleus. Analysis of the GmLFY genomic structure showed that the GmLFY gene has two introns with similar spliced sites as LFY-like genes in other plants. Reverse transcription-polymerase chain reaction (RT-PCR) analysis indicated that GmLFY was predominantly expressed in reproductive organs, such as inflorescences, pods and developing seeds. Further analysis showed that the expression level of GmLFY was higher in the middle stage than in the early or late stages of seed development, suggesting an essential regulatory role of GmLFY in soybean seed development.