Salinity is a serious factor limiting the productivity of agricultural plants. One of the potential problems for plants growing under saline conditions is the inability to up take enough K+. The addition of K+ may considerably improve the salt tolerance of plants grown under salinity. It is assumed that increasing the K+ supply at the root zone can ameliorate the reduction in growth imposed by high salinity. The present study aims to determine whether an increase in the K/Na ratio in the external media would enhance the growth of date palm seedlings under in vitro saline conditions. Date palm plants were grown at four concentrations of Na + K/Cl (mol/m3) with three different K/Na ratios. The 12 salt treatments were added to modified MS medium. The modified MS medium was further supplemented with sucrose at 30 g/l. Growth decreased substantially with increasing salinity. Growth expressed as shoot and root weight, enhanced significantly with certain K/Na ratios, and higher weight was maintained in the presence of equal K and Na. It is the leaf length, leaf thickness and root thickness that had significant contribution on total dry weight. Na+ contents in leaf and root increased significantly increased with increasing salinity but substantial decreases in Na+ contents were observed in the leaf and root with certain K/Na ratios. This could be attributed to the presence of a high K+ concentration in the media. The internal Na+ concentration was higher in the roots in all treatments, which might indicate a mechanism excluding Na+ from the leaves and its retention in the roots. K/Na ratios up to one significantly increased the leaf and root K+ concentration, and it was most pronounced in leaves. The K+ contents in leaf and root was not proportional to the K+ increase in the media, showing a high affinity for K+ uptake at lower external K+ concentrations, but this mechanism continues to operate even with high external Na+ concentrations. Increasing K/Na ratios in the growing media of date plam significantly reduced the absorption of Na+ less than 200 mM and also balance ions compartmentalization.

Jojoba (Simmondsia Chinensis L.) is a dioecious perennial evergreen shrub native to the south-western desert of North America and has now been introduced to Middles East. Currently, there is low production of jojoba globally, mainly due to the high male-to-female ratio in the plantations since they are mainly established from seed. Hence, a proper population stand in terms of the male: female ratio is almost impossible to maintain in the field, leading to reduced production. We report a breakthrough in the methodology for determining the sex of jojoba plants. Our research revealed that the jojoba genome contains the sequence of SRY gene, which encodes a protein similar to that found in the human Sex-Determining Region (SRY) gene. This region was amplified and matched with sequences found in papaya and human. The jojoba-SRY regions (SRY gene) was amplified, and we closely matched with sequences of SRY in the papaya and human. The complete sequence of the DNA was deposited in GenBank (BankIt MK991776,3 60pb). Our newly developed method is rapid and straightforward, representing a breakthrough for sex determination strategies of jojoba plants to identify sex at early developmental stages. The uniqueness of this approach is that it targets specific sequences in SRY, a region extensively studied in human genetics but also apparently recognizable in plants. This useful molecular diagnostic tool is vital in agronomical breeding programs for sex determination in long-lived jojoba crops.