Salinity is reported to reduce chickpea yield by impairing plant growth and N-fixation efficiency. This research sought to investigate salt tolerance in chickpea, chickpea rhizobia and their symbiosis. The aim was to optimize cultivar-symbiont associations following the screening of a number of chickpea and rhizobia accessions and to evaluate their performance in saline conditions. Salinity levels of 0 and 20 dS/m of NaCl+Na2S04 were used for screening 18 chickpea rhizobia and 0,8,16,24 and 32 dS/m were used for screening 9 chickpea genotypes. The effect on the growth of rhizobia was an extension of the lag phase and/or a slowing down of the log phase. Some strains tolerated 20 dS/m, while others completely failed to grow at the same level of salinity. The tolerant strains CP-32 and CP-29 were selected. Screening 9 chickpea genotypes during germination and early seedling growth indicated that the highest salt tolerance ILC-205 and ILC-1919 had. The selected rhizobial strains and chickpea cultivars were laid out in a arrangement in a pot experiment aimed at investigating the effect of three salinity levels (3 dS/m, 6 dS/m and 9 dS/m) and a no salt control on symbiosis and plant growth. A treatment with mineral N and a no nitrogen treatment were also included. Results revealed that salinity affected the N-fixing plants more than the N-fed plants although the former showed similar or significantly better shoot dry weight and N content than the N-fed plants when no salt was added. Significant reductions in nodule dry weight (59.8%) and N-fixation (63.5%) were evident even at the lowest salinity level of 3 dS/m. Unlike ILC-205, ILC-1919 exhibited no significant reduction in root dry weight and nodule number up to 3 dS/m. Although the inoculated plants continued nodulation up to 6 dS/m, N-fixation was completely inhibited at the same level of salinity. These findings indicated differences in the salt sensitivity of the various processes involved in symbiotic N fixation. These include host recognition, root hair infection, nodule initiation and development and N-fixation. Moreover, the higher salt tolerance of the N-fed plants compared to the N-fixing plants reflected the fact that symbiosis is more salt sensitive than both rhizobia and plant alone. Thus, the amelioration of N-fixation in saline environments is contingent on the identification and improvement of the rate limiting process. Improvement of salinity tolerance in the field may be achieved by supplementing crops with sufficient amounts of mineral nitrogen.
- ISBN 10 : OCLC:785039743
- Judul : Response of Chickpea Nodulation, Nitrogen Fixation and Growth to Salinity
- Pengarang : Mohamed Ahmed Mohamed Adlan,
- Kategori : Chickpea
- Bahasa : en
- Tahun : 1995
- Halaman : 230
- Halaman : 230
- Google Book : http://books.google.co.id/books?id=5t8TMwEACAAJ&dq=inauthor:adlan&hl=&source=gbs_api
Salinity is reported to reduce chickpea yield by impairing plant growth and N-fixation efficiency.