PRELIMINARY EVALUATION OF GRAIN AMARANTH (Amaranthus spp.) ACCESSIONS FOR DROUGHT TOLERANCE BY MULTIVARIATE TECHNIQUE

Ciljevi ovog pokusa bili su usporediti različite pokazatelje tolerantnosti na sušu za predviđanje tolerantnosti na sušu i procijeniti trideset potomaka zrnatog amaranta (Amaranthus spp.) na tolerantnost na sušu primjenom nekoliko pokazatelja tolerantnosti na sušu. Sjeme trideset (30) potomaka zrnatog amaranta sakupljeno u Nacionalnom poljoprivrednom istraživačkom institutu (NIHORT) u Ibadanu selekcionirano je 2011. godine u Selekcijskom centru NIHORT-a. Sjeme je uzgajano u rasadniku tri tjedna i zatim presađeno u polietilenske vreće. Uveden je vodeni stres 4, 6 i 8 tjedana nakon presađivanja (WAT), a kontrola je provedena u 100% terenskim uvjetima. Pokus je bio potpuno randomiziran plan (CRD) postavljen u faktorijalnom rasporedu 4 x 30 u tri ponavljanja. Upotrijebljeni su agronomski podaci i pokazatelji tolerantnosti na sušu za procjenu performance zrna amaranta. Obavljena je analiza varijance (ANOVA) da se ustanovi značajan učinak (P0,05) je smanjio visinu biljke, te broj listova i grančica amaranta. Amarant je u terenskim uvjetima dao značajno (P<0,05) veći prinos sjemena od amaranta pod stresom od 8 WAT-a (54 odnosno 25 gbiljaka-1) Prinos sjemena bio je u znatnoj pozitivnoj korelaciji s duljinom korijena (r=0,86++), suhom težinom izdanka (r=0,79**), STI (r=0,96**, GMP (re=0,97** i HM(r=0,95**), ali ne sa SSI. Analiza klastera je pokazala da su potomci imali tendenciju kategorizacije u tri skupine na razini 96% sličnosti, potomci AMES 5647, PI576464, PI576483 i PI576483 imali su najviši STI, GMP, MP, HM i prema tome su smatrani najpoželjnijim klasterom u oba uvjeta. U zaključku, ovaj je rad pokazao da se selekcija na tolerantnost na sušu može temeljiti na STI, GMP, MP i HM na osnovi njihove značajne pozitivne korelacije s prinosom zrna.The objectives of this experiment were to compare different drought tolerance indices for drought tolerance prediction and evaluate thirty accessions of grain amaranth (Amaranthus spp.) for drought tolerance using several drought tolerance indices. Seeds of thirty (30) accessions of grain amaranth collected from National Horticultural Research Institute (NIHORT), Ibadan were screened in 2011 at the screen house of NIHORT. Seeds were raised in nursery for three weeks and later transplanted into polyethylene bags. Water stress was imposed at 4, 6 and 8 weeks after transplanting (WAT) and the control was maintained at 100 % field capacity. The trial was a completely randomized design (CRD) laid out in a 4 × 30 factorial arrangement replicated three times. Agronomic data and drought tolerance indices were used to assess the performance of grain amaranth. Analysis of variance (ANOVA) was performed to establish significant effect (P ≤ 0.05; F-test) of the treatments on the parameters taken, significant means were separated using standard error of the difference of means in post ANOVA t-tests. Result of the experiment showed that grain amaranth stressed at 4 and 6 WAT died before reaching maturity, water stress significantly (P < 0.05) reduced plant height, number of leaves and branches of grain amaranth. Grain amaranth at field capacity produced significantly (P < 0.05) higher seed yield than those stressed at 8WAT (54 and 25 gplant-1 respectively). Seed yield had significant positive correlation with root length (r = 0.86**), shoot dry weight (r = 0.79**), STI (r = 0.96**), GMP (r = 0.97**) and HM (r = 0.95**) but not with SSI. Cluster analysis indicated that the accessions tended to be categorized into three groups at 96 % similarity level, accession AMES5647, PI576464, PI576454 and PI576483 had the highest STI, GMP, MP, HM and was thus considered to be the most desirable cluster for both conditions. In conclusion, this study showed that selection for drought tolerance could be based on STI, GMP, MP, HM based on their significant positive correlation with grain yield