Association studies between grain yield and agronomic traits of a MARS maize (Zea mays L.) population under drought and non-stress condition | Raziskava povezav med pridelkom zrnja in agronomskimi lastnostmi populacij koruze (Zea mays L.) v razmerah suše in v nestresnih razmerah

English. The study aimed at examining the associations between yield and other traits under drought stress and non-stress conditions. A total of 150 MARS testcrosses were evaluated under both conditions at the International Institute of Tropical Agriculture substation for two years under during the dry season. Genotypic and phenotypic correlation, multiple stepwise regression and path co-efficient analyses were carried out to examine the relationship among the traits under both environments. Results showed anthesis-silking interval, days to silking, husk cover and plant aspect were significantly associated with yield under drought condition at both genotypic and phenotypic levels. Yield was positively correlated with plant and ear height but had a negative correlation with plant and ear aspect at both levels under well-watered condition. Regression analysis showed that ears per plant, plant aspect, ear aspect, days to silking, leaf death and plant height had a direct effect on yield, contributing a total of 71.1 % of observed variation under drought, while ears per plant, ear aspect, plant aspect, days to pollen shed, days to silking and plant height contributed about 31.42 % to yield under well-watered conditions. The study concluded that these traits be used as selection criteria as it will aid improvement of maize yield.

Slovenian. Namen raziskave je bil preučiti povezave med pridelkom zrnja in drugimi lastnostmi koruze v razmerah suše in v nestresnih razmerah. Na International Institute of Tropical Agriculture je bilo ovrednotenih 150 križanj v obeh razmerah v dveh letih, v sušni sezoni. Genotipska in fenotipska korelacija, postopna multipla regresija in koeficient korelacije med neposredno odvisnimi spremenljivkami so bili opravljeni za preučitev razmerja med lastnostmi v obeh rastnih razmerah. Rezultati so pokazali, da so bili znaki kot so obdobje anteza-sviljenje, dnevi do sviljenja in pokritost storža značilno povezani s pridelkom v sušnih razmerah na genotipski in fenotipski ravni. Pridelek je bil v pozitivni korelaciji z višino rastlin in višino storžev na rastlini, a je bil v negativni korelaciji z drugimi aspekti rastline in storža v razmerah dobre oskrbe z vodo. Analiza regresije je pokazala, da so imeli znaki kot so število storžev na rastlino, aspekt rastline in storža, dnevi do sviljenja, smrtnost listov in višina rastlin neposreden učinek na pridelek in so prispevali skupaj 71,1 % opažene spremenljivosti v sušnih razmerah, medtem ko so ti isti znaki prispevali le 31,42 % vpliva na pridelek v razmerah dobre oskrbe z vodo. Na osnovi te raziskave je bilo zaključeno, da bi lahko te lastnosti (znake) uporabili kot selekcijske kriterije, ki bi pomagali izboljšati pridelek koruze.