Screening for Drought Tolerance in Selected Chickpea (Cicer arietinum L.) germplasm in Nakuru and Baringo Counties of Kenya
Kirui, Grace Jerotich
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Thereis currently an acute food shortage in Kenya, mainly caused by crop failure resulting fromdrought and unreliable rainfall, especially in arid and semi-arid regions which consists of approximately 80% of total land area. Drought has been spreading to more land in Kenya over the years due to climatic change attributed to global warming. There is thereforeneed to research on crops that are high yielding and drought tolerant. Chickpea beingdrought resistant can offer an alternative food crop since it has the highest nutritional compositionsof any dry edible legume and can be produced under low rainfall and poor soils.In addition chickpea can act as a cereal-legume relay crop in dry highlands during the shortrains as it improves soil fertility and conserves moisture. But currently there are no linesreleased for commercial production in Kenya, hence there is need to introduce and evaluateseveral lines to identify those that can do well in dry lands of Kenya. This study therefore screened several chickpea genotypes to identify and select high yielding and droughttolerant lines with associated morpho-physiological characteristics under field conditionsand determined their heritability. The study was done in two sites, at Koibatek- FarmersTraining Center for two seasons (during the short and long rains) and in KEPms- Lanetfor one season (long rains). A mini core collection of 30 lines from ICRISAT was evaluatedin the two sites in a Randornised Complete Block Design (RCBD), replicated twice.Parameters that were measured included phenological growth stages, yield (Kg/ha) andits components which included number of pods/plant, plant height (em), plant spread (em),biomass (Kg/ha), harvest index (Hl). All data collected were analyzed using Analysis ofVariance(ANOV A) using Genstat and means separated by Duncan Multiple Range Test (DMRT)at (P=0.05). ). Heritability of traits was determined using broad sense heritability (h').Analysis of variance showed no significant difference in yield among lines, (P=0.905) but there was a significant difference in the sites at (P = O.OOl).Yield (Kg/ha) had insignificantpositive correlation with days to 50% flowering (r = 0.121), biological mass Kglha(r = 0.160), days to physiological maturity (r = 0.138), and percentage drought toleranceefficiency (DTE) (r = 0.177). There was negative correlation between yield and droughtindex (r = -0.051), harvest index (r = -0.055) and spread (em) (r = -0.114). When yieldand ability to tolerate drought were both considered, the lines selected to be drought toleranceincluded; IG 10500, ICC 9895, ICC 6537, ICC 2679 and ICCV 95311. % DTE andyield formed the basis for selection for drought tolerance. The morphological traits associated with drought tolerance due to their direct contribution to yield included biologicalmass, days to physiological maturity, days to 50% flowering and % DTE. Heritabilityindex results showed that spread, days to first podding, days to first flowering, droughtindex, % DTE and days to physiological maturity had higher heritability index thanthat of the yield. Thus, these traits could be of interest in improving chickpea since theycould be genetically manipulated or improved due to their high genetic contribution to theirphenotypic traits. Lines which had high DTE which included ICC1923, ICC2679, ICC6537, ICC7571 and ICC1422, should further be tested to confirm their drought tolerancecharacteristics for utilization in improvement of the selected chickpea lines. Thereis need for further screening and breeding of the selected lines for drought tolerance.