Morphometry of chincuya seeds (Annona purpurea Moc. &Sessé ex Dunal) and embryonic growth under dry warm storage

Abstract

In Mexico, Annona purpurea Moc. &Sessé ex Dunal, chincuya is found in mountains and family gardens. It is used as food (fruits), traditional medicine (leaves, stems, roots, seeds, bark), wood in construction, papermaking, carpentry, rope making, and as fuel. There is not enough information on the seed, nor on germination management, which is scarce, prolonged and erratic. Considering that the morphophysiological dormancy is the probable cause, it was necessary, within a broader project, to start with the characterization of the seed and determine the effect of dry warm storage (DWS) on it. The perimeter and length of the embryos increased due to the increase in length of the cotyledons and the hypocotil root axis, while the middle hypocotyl area decreased, forming an acinturated embryo. These data indicate that the embryos of chincuya are underdeveloped since they grew and modified their shape, due to the effect of DWS, until the 6th month. This development of the embryo within the seed during dry warm storage confirms the presence of morphological dormancy. This is the first report of embryo growth and characterization of chincuya seeds.

Effect of Warm-Dry Storage and Supplemental Application of Gibberellins on the Lipid Profile of Chincuya Seeds (Annona purpurea Moc. & Sessé ex Dunal)

“…A sudden drop in viability occurred on the twelfth month of storage (Figure 2). Vidal-Lezama et al noted that embryos grew during warm-dry storage until the sixth month [8], coinciding with the viability data observed here. Similarly, González-Esquinca et al found that A. macroprophyllata seed viability did not change throughout the 8-month storage evaluation [11].…”

“…Other mechanisms that might explain the after-ripening effect include non-enzymatic reactions that eliminate germination inhibitors, reactive oxygen species, and antioxidants [36], membrane alterations [37], and specific protein degradation through the proteasome [38]. Taiz and Zeiger mention that developing seeds synthesize gibberellins [19], and following the results found by Vidal-Lezama et al, who pointed out that chincuya embryos grow during warm-dry storage [8], it is possible to assume a continuum in the synthesis of gibberellins (although not exclusively) in the seed. On the other hand, the location of the species in the phylogenetic tree and its relationship with dormancy should be noted.…”

“…September was the rainiest month, with an average of 27.4% of the rainy months. The large seed size is due to the species' habitat [8] compared to other Annona species and rainfall seasonality. The functional strategy of the seeds is likely to maintain metabolic activity at a lower rate than when they were inside the fruit and attached to the tree; for this, the dormancy manifests as a germination delay.…”

“…Therefore, studies related to embryo growth must be carried out to demonstrate it [7] Vidal-Lezama et al [8] showed that chincuya seeds have morphological dormancy. The warm-dry storage treatment overcame this latency by causing morphological changes in the embryo and its growth.…”

Warm Dry Storage and Application of Gibberellins in The Lipid Profile of Chincuya Seeds (Annona purpurea Moc. & Sessé ex Dunal)

“…The highest viability corresponded to months 6 and 9, although without statistical significance, except in the twelfth month where viability suddenly decreased. However, [29] it was pointed out that with the same storage, embryos grew until the sixth month. Similarly, [11] found that the A. macroprophyllata seed viability does not change throughout the 8-month storage evaluation.…”