It has been demonstrated that postharvest calcium application enhanced lenticels breakdown (LB), occurring after storage. In this study, we examined whether preharvest in-orchard calcium foliar application can also enhances lenticels breakdown. Calcium foliar application was examined on fruit harvested separately from northern and southern sides of the trees in two orchards. Four in-orchard treatments were applied: No treatment (Control), CaCl2, Ca(NO3)2 and KCl. The orchards were located in regions with different climatic conditions. LB damage was higher in the low humidity orchard in comparison to that in the higher humidity orchard. Moreover, LB was enhanced by preharvest calcium application only in apples from the northern side of the trees, located in the lower relative humidity orchard. Preharvest calcium application reduced the peel thickness of apples from both tree sides in the high relative humidity orchard, and only in the northern side of the low humidity orchard. Hence, in-orchard calcium foliar application can enhance LB only under specific field climate conditions. Reduced peel thickness by calcium in the northern side of the low relative humidity orchard, might have led to a higher post storage LB. Nevertheless, the status of open lenticels at harvest can only partially explain the postharvest LB. In addition, the force needed to puncture the peel does not explain LB results. In conclusion, this study supports the finding that calcium increases LB, but only under certain environmental conditions.

'Runner' and 'Virginia', the two main market types of Arachis hypogaea subspecies hypogaea, differ in several agricultural and industrial characteristics. One such trait is time to maturation (TTM), contributing to the specific environmental adaptability of each subspecies. However, little is known regarding TTM's genetic and molecular control in peanut in general, and particularly in the Runner/Virginia background. Here, a recombinant inbred line population, originating from a cross between an early-maturing Virginia and a late-maturing Runner type, was used to detect quantitative trait loci (QTL) for maturity. An Arachis SNP-array was used for genotyping, and a genetic map with 1425 SNP loci spanning 24 linkage groups was constructed. Six significant QTLs were identified for the maturity index (MI) trait on chromosomes A04, A08, B02 and B04. Two sets of stable QTLs in the same loci were identified, namely qMIA04a,b and qMIA08_2a,b with 11.5%, 8.1% and 7.3%, 8.2% of phenotypic variation explained respectively in two environments. Interestingly, one consistent QTL, qMIA04a,b, overlapped with the previously reported QTL in a Virginia × Virginia population having the same early-maturing parent ('Harari') in common. The information and materials generated here can promote informed targeting of peanut idiotypes by indirect marker-assisted selection.

Lenticel breakdown (LB) mainly occurs in susceptible 'Gala' and 'Red Delicious' apples following storage. Postharvest calcium treatment increased LB of both cultiavrs as well as the less susceptible 'Orleans' and 'Granny Smith'. Calcium increased the number and size of damaged lenticels. Callose was deposited in the sub-lenticular cells and the cuticle of the damaged lenticels, as well as in non- damaged lenticels. Suberin was deposited in the sub-lenticular cells, but only in the most severely damaged lenticels, and especially in calcium-treated fruit. Postharvest calcium treatment increased the micro- cracking of the skin surface and removed the epicuticullar wax following storage. It also decreased the thickness of the cutin and wax layers. Gene expression, mainly of those involved in the wax biosynthesis and cutin and wax transport, were reduced in peel of calcium-treated fruit. Our study suggests that the deleterious effect of calcium on fruit skin occurs due to a decrease in cuticle deposition during storage, resulting in a thinner cuticle, leading to micro-cracks, which culminates in increased lenticel damage.