Year : 2005, Volume : 32, Issue : 1 and 2
Print ISSN : 0970-8235.
Nutrient management by exploiting genetic diversity of potato – A review
Author: Trehan S.P.
Institution: Central Potato Research Station, P.B.No. 1, P.O. Model Town, Jalandhar 144 003, Punjab, India
The new millennium will put more pressure on soil fertility due to growing human needs and urge for economic gains. Abiotic stresses will require improved crops which are more efficient in performing well under degraded and denuded soil conditions (25). Thus, there is a need to select/breed crops/varieties which could withstand such stresses without depressing yields. Screening of plant materials most efficient in nutrient-deficient conditions is, therefore, required. Identifying promising genes or genotype for response to different stresses will open new frontiers for exploration of biotechnology. This information will help crop improvement programmes to tailor the crops and their varieties to withstand varying degrees of stresses. The identification of nutrient efficient plant and root/shoot parameters controlling nutrient use efficiency will help greatly in nutrient budgeting in addition to providing a sustainable base for enhancing food quality as well as quantity.
This research found that different plant species and potato cultivars differed in nutrient use efficiency. Potassium (K) efficiency was lowest for potato followed by wheat and sugar beet. Potato had a similar total K requirement as wheat. Wheat and sugar beet were similarly K efficient. Wheat had a lower K requirement than sugar beet but more roots, therefore, a small influx was sufficient. Sugar beet had a high K requirement and fewer roots. Maize was less Zn-efficient than potato and sunflower. The low Zn–uptake efficiency of maize was associated with a low Zn influx which nullified the effect of its high root-DMA ratio. Potato cv. Kufri Chandramukhi had a higher K uptake efficiency than Kufri Badshah and Kufri Jyoti. Kufri Chandramukhi main–tained higher K influx by utilizing more non-exchangeable soil K than Kufri Jyoti and Kufri Badshah. However, potato cv. Kufri Chandramukhi had a lower Zn uptake efficiency than cv. Kufri Badshah due to its lower root-DMA ratio than Kufri Badshah because Zn influx was similar in both the cultivars. Kufri Chandramukhi was more P efficient than Kufri Badshah and Kufri Pukhraj. Roots of P–efficient genotypes had the capacity to keep more applied P in available form than inefficient genotypes.
Comparison of DNA finger prints of these genotypes revealed the genetical variation in the genotypes, responsible for different nutrient use efficiency. Potassium efficient species and cultivars maintained higher K influx by using higher amount of less mobile soil K (non-exchangeable K) whereas phosphorus efficient cultivars had shown higher P influx due to the capability of their roots to reduce fixation of applied P in the soil. Higher root growth (root-shoot/DMA ratio) was respon–sible for higher zinc efficiency of potato cultivars.